There is disclosed a correlating operation method and a matched filter in which sensitivities in received code sequence selection and path detection are held to some degrees while circuit scale can be reduced. In the correlating operation method and the matched filter, code data obtained by adding or subtracting an in-phase component and a quadrature component of a received code sequence in a code mapping unit, and an in-phase component and a quadrature component of a received complex signal are subjected to correlating operation, and a correlating operation result is subjected to power adding operation to obtain a correlating operation output.

1. Field of the Invention
The present invention relates to a correlator (matched filter) used in de-spreading method on a receiver in code division multiple access (CDMA) for use in a spread spectrum communication system, particularly to a matched filter which can reduce a circuit scale without deteriorating a path detection sensitivity.
2. Description of the Related Art
In a CDMA system, after primary modulation of information data is performed in a transmitting unit, code modulation (secondary modulation) is performed using a sequence of codes (a sequence of transmitted codes) having a faster rate than that of the data modulation (primary modulation), so that a transmitted complex signal is generated.
In CDMA data communication in which quadrature phase shift keying (QPSK) is used as a system of modulating the information data and codes, when the information data is set to S, and the transmitted code sequence is set to C, a transmitted complex signal TX can be represented as follows:                                                         TX              =                              S                ·                C                                                                                =                                                (                                      Si                    +                                          j                                                                    xe2x80x83                                                                  Sq                                                        )                                ·                                  (                                      Ci                    +                                          j                                                                    xe2x80x83                                                                  Cq                                                        )                                                                                =                                                (                                                            Si                      ·                      Ci                                        -                                          Sq                      ·                      Cq                                                        )                                +                                  j                                                        (                                                                  Si                        ·                        Cq                                            +                                              Sq                        ·                        Ci                                                              )                                                                                =                              TXi                +                                  j                                                        xe2x80x83                                                      TXq                                                                                [                  Equation                                xe2x80x83                              1                ]
Here, for the information data S, when an in-phase component is represented by Si, and a quadrature component is represented by Sq, the in-phase component and the quadrature component are in an orthogonal relation, and the quadrature component Sq is multiplied by an imaginary number j and represented. Similarly, for the code sequence C, when an in-phase component is represented by Ci, and a quadrature component is represented by Cq, the in-phase component and the quadrature component are in the orthogonal relation, and the quadrature component Cq is multiplied by the imaginary number j and represented.
Furthermore, when the transmission information data is taken from the transmitted complex signal, that is, the data demodulation (de-spreading) is performed on the side of the receiving unit, the received complex signal and the transmitted code sequence used in the spreading modulation need to be subjected to the complex conjugate correlating operation.
In this case, a searcher for use on the receiver side of the CDMA system has a role of synchronization capture to select a code which is complex/conjugate with the transmitted code sequence used in the spreading modulation on the transmission side, that is, an accurate received code sequence, and further to find the transmission timing of the transmitted complex signal.
A procedure of selecting the received code sequence in the searcher comprises, in the same manner as in the data demodulation, performing the complex conjugate correlating operation of the received complex signal and the received code sequence, and performing power adding operation with respect to the operation result of the in-phase component and the quadrature component.
Here, a principle of selecting the received code sequence in the searcher will be described.
A first case will be described in which a certain code sequence C* in a complex conjugate relation with the transmitted code sequence used for generating the transmitted complex signal in the transmitter is used as a received code sequence during the correlating operation of the searcher.
Assuming that a transmitted complex signal is TX, the transmitted complex signal TX is subjected to code modulation as shown in [Equation 1] in the transmitting unit, and that the transmitted complex signal TX is received as it is to form a received complex signal, a correlating operation result R1 of the code sequence C* having the complex conjugate relation with the transmitted code sequence C, and the transmitted (received) complex signal TX is represented by the following equation:                                                         R1              =                              xe2x80x83                                                          TX                ·                                  C                  *                                                                                =                              xe2x80x83                                                                            (                                      TXi                    +                                          j                                                                    xe2x80x83                                                                  TXq                                                        )                                ·                                  (                                      Ci                    -                                          j                                                                    xe2x80x83                                                                  Cq                                                        )                                                                                =                              xe2x80x83                                                                            TXi                  ·                  Ci                                +                                  TXq                  ·                  Cq                                +                                  j                                                        (                                                                  TXq                        ·                        Ci                                            -                                              TXi                        ·                        Cq                                                              )                                                                                [                  Equation                                xe2x80x83                              2                ]
In the above [Equation 2], the multiplying (correlating) operations of the in-phase component TXi and quadrature component TXq of the received complex signal, and the in-phase component Ci and quadrature component Cq of the received code sequence used in the searcher are independently performed. This means that four correlators have to be prepared as hardware.
Moreover, for the second stage of the above [Equation 2], when TXi+jTXq is developed according to [Equation 1], the following is obtained:                     R1        =                  xe2x80x83                                              {                                          (                                                      Si                    ·                    Ci                                    -                                      Sq                    ·                    Cq                                                  )                            +                              j                                                  (                                                            Si                      ·                      Cq                                        +                                          Sq                      ·                      Ci                                                        )                                                      }                    ·                      (                          Ci              -                              j                                                  xe2x80x83                                                Cq                                      )                                                  =                  xe2x80x83                                              (                                          Si                ·                Ci                ·                Ci                            -                              Sq                ·                Cq                ·                Ci                            +                              Si                ·                Cq                ·                Cq                            +                              Sq                ·                Ci                ·                Cq                                      )                    +                                                  xe2x80x83                                  j                                (                                          Si                ·                Cq                ·                Ci                            +                              Sq                ·                Ci                ·                Ci                            -                              Si                ·                Ci                ·                Cq                            +                              Sq                ·                Cq                ·                Cq                                      )
When the multiplication of the code sequence is represented as a correlating operation result by a correlation function Rxx, the following is obtained:                                                         =                              xe2x80x83                                                                            (                                                            Si                      ·                      Rii                                        -                                          Sq                      ·                      Riq                                        +                                          Si                      ·                      Rqq                                        +                                          Sq                      ·                      Riq                                                        )                                +                                                                                xe2x80x83                                                          j                                                  (                                                            Si                      ·                      Riq                                        +                                          Sq                      ·                      Rii                                        -                                          Si                      ·                      Riq                                        +                                          Sq                      ·                      Rqq                                                        )                                                                                =                              xe2x80x83                                                                            Si                  ·                                      (                                          Rii                      +                      Rqq                                        )                                                  +                                  j                                                        xe2x80x83                                                                          Sq                    ·                                          (                                              Rii                        +                        Rqq                                            )                                                                                [                  Equation                                xe2x80x83                              3                ]
Here, the correlation function Rxx indicates the correlating operation result of a certain code sequence and another code sequence. When two affixed letters are the same, a result (auto-correlation function) of the correlating operation of the same code sequence is indicated. When the affixed letters are different, the function is classified as a result (cross-correlation function) of the correlating operation of different code sequence.
Here, for the system of codes in the CDMA system, the auto-correlation function is highest, and the cross-correlation function has a sufficiently small value as compared with the auto-correlation function. Therefore, for the sake of simplicity, the auto-correlation function is defined as 1, and the cross-correlation function is defined as 0 in the description.
According to the above-described definition, the correlating operation result R1 of the searcher obtained by [Equation 3] can be represented as follows:
R1=2xc2x7Si+j2xc2x7Sq=X+jYxe2x80x83xe2x80x83[Equation 4]
When power adding operation is performed on the operation result of the in-phase component and the quadrature component obtained by [Equation 4], the following results:
P1=|X|2+|Y|2=4xc2x7(|Si|2+|Sq|2)
For the information data Si, Sq, when data of xc2x11 is transmitted, the following result is obtained:
P1=4xc2x7(1+1)=8
This means that when the received code sequence comprises the code sequence C* having the complex conjugate relation with the transmitted code sequence C, the power adding operation P1 obtains a constant value of 8 irrespective of the content of transmission information (information data Si, Sq).
A second case will next be described in which a code sequence Cn not placed in the complex conjugate relation with the transmitted code sequence C used for generating the transmitted complex signal in the transmitter is used as the received code sequence in the correlating operation of the searcher.
In the same manner as in the first case, assuming that the transmitted complex signal is TX, the transmitted complex signal TX is subjected to the code modulation as shown in [Equation 1] in the transmitting unit, and the transmitted complex signal TX is received as it is to form a received complex signal, a correlating operation result R2 of the code sequence Cn not placed in the complex conjugate relation with the code sequence C, and the transmitted (received) complex signal TX is represented and developed by the following equation:                                                         R2              =                              xe2x80x83                                                          TX                ·                Cn                                                                                =                              xe2x80x83                                                                            (                                      TXi                    +                                          j                                                                    xe2x80x83                                                                  T                                                                    xe2x80x83                                                                  Xq                                                        )                                ·                                  (                                      Ck                    -                                          j                                                                    xe2x80x83                                                                  Cr                                                        )                                                                                =                              xe2x80x83                                                                            {                                                            (                                                                        Si                          ·                          Ci                                                -                                                  Sq                          ·                          Cq                                                                    )                                        +                                          j                                                                    xe2x80x83                                                                                (                                                                              Si                            ·                            Cq                                                    +                                                      Sq                            ·                            Ci                                                                          )                                                                              }                                ·                                  (                                      Ck                    -                                          j                                                                    xe2x80x83                                                                  Cr                                                        )                                                                                =                              xe2x80x83                                                                            (                                                            Si                      ·                      Rik                                        -                                          Sq                      ·                      Rkq                                        +                                          Si                      ·                      Rqr                                        +                                          Sq                      ·                      Rir                                                        )                                +                                                                                xe2x80x83                                                          j                                                  (                                                            Si                      ·                      Rkq                                        +                                          Sq                      ·                      Rik                                        -                                          Si                      ·                      Rir                                        +                                          Sq                      ·                      Rqr                                                        )                                                                                [                  Equation                                xe2x80x83                              5                ]
Here, since the correlation functions Rxx in [Equation 5] are all cross-correlation functions, it can be seen that Rxx=0, and R2=0.
As apparent from the power adding operation results R1, R2 in the above-described two cases, only when the transmitted code sequence C used in the transmitter and the received code sequence used in the operation of the searcher are in the complex conjugate relation, a large power adding operation result is obtained.
Specifically, by referring to the level of the power adding operation result, it can be judged whether the transmitted code sequence C on the transmission side and the received code sequence selected on the reception side agree with each other.
Moreover, when the above-described power adding operation result is observed with time, a large power adding operation result output is obtained at a certain timing. Since the appearing timing is a transmitted signal timing to which the influence of propagation in air is added, path detection can also be realized by observing a large power adding operation result output.
In an example as one measure for realizing the correlator for the searcher to perform the correlating operation of the transmitted complex signal and the received code sequence, a matched filter is used.
Here, the conventional constitution example of the matched filter used as the correlator for the searcher will be described with reference to FIG. 6. FIG. 6 is a constitution block diagram of the conventional matched filter.
The conventional matched filter is constituted of four correlating operators 101xe2x80x2, 102xe2x80x2, 103xe2x80x2, 104xe2x80x2, two adders 105xe2x80x2, 106xe2x80x2, and a power adding operator 107xe2x80x2.
Each component of the conventional matched filter will be described.
The correlating operator 101xe2x80x2 is a correlating operator (MF Ich-1 in FIG. 6) which inputs the in-phase component TXi (Mod-I in FIG. 6) of the received complex signal TX, and the in-phase component Ci of the received code sequence C* (Code-I in FIG. 6) and takes the correlation of both components to output a correlation result.
Additionally, this correlating operator 101xe2x80x2 realizes the operation of a first term (TXixc2x7Ci) in the rightmost side of the above-described [Equation 2].
The inside of the correlating operator 101xe2x80x2 is constituted of a data register 111xe2x80x2 formed of a plurality of shift registers for successively time-shifting and holding the in-phase component TXi of the received complex signal TX, a code register 112 for successively time-shifting and holding the in-phase component Ci of the received code sequence C*, a plurality of multipliers 113xe2x80x2 for performing multiplication of the data held by the data register 111xe2x80x2 and the data held by the code register 112, and an adder 114xe2x80x2 for adding multiplication results in the multipliers 113xe2x80x2.
The correlating operator 102xe2x80x2 is a correlating operator (MF Ich-2 in FIG. 6) which inputs the quadrature component TXq (Mod-Q in FIG. 6) of the received complex signal TX and the quadrature component Cq (Code-Q in FIG. 6) of the received code sequence C* and takes the correlation of both components to output a correlation result.
Additionally, this correlating operator 102xe2x80x2 realizes the operation of the second term (TXqxc2x7Cq) in the rightmost side of the above-described [Equation 2].
The correlating operator 103xe2x80x2 is a correlating operator (MF Qch-1 in FIG. 6) which inputs the quadrature component TXq (Mod-Q in FIG. 6) of the received complex signal TX and the in-phase component Ci (Code-I in FIG. 6) of the received code sequence C* and takes the correlation of both components to output a correlation result.
Additionally, this correlating operator 103xe2x80x2 realizes the operation of the third term (TXqxc2x7Ci) in the rightmost side of the above-described [Equation 2].
The correlating operator 104xe2x80x2 is a correlating operator (MF Qch-2 in FIG. 6) which inputs the in-phase component TXi (Mod-I in FIG. 6) of the received complex signal TX and the quadrature component Cq (Code-Q in FIG. 6) of the received code sequence C* and takes the correlation of both components to output a correlation result.
Additionally, this correlating operator 104xe2x80x2 realizes the operation of the fourth term (TXixc2x7Cq) in the rightmost side of the above-described [Equation 2].
Since the inside of the correlating operator 102xe2x80x2, 103xe2x80x2 or 104xe2x80x2 is similar to that of the correlating operator 101xe2x80x2, it is not shown in FIG. 6, but it is constituted of a data register for successively time-shifting and holding the received complex signal TX inputted in each correlating operator, a code register for successively time-shifting and holding the received code sequence C*, a plurality of multipliers for performing multiplication of the data held by the data register and the data held by the code register, and an adder for adding multiplication results in the multipliers.
The adder 105xe2x80x2 is an in-phase component adder for adding the correlation result from the correlating operator 101xe2x80x2 and the correlation result from the correlating operator 102xe2x80x2 to output an in-phase component correlation result.
Additionally, this adder 105xe2x80x2 realizes the adding operation of the first and second terms in the rightmost side of the above-described [Equation 2].
The adder 106xe2x80x2 is a quadrature component adder for adding the correlation result from the correlating operator 103xe2x80x2 and the correlation result from the correlating operator 104xe2x80x2 to output a quadrature component correlation result.
Additionally, this adder 106xe2x80x2 realizes the subtracting operation of the third and fourth terms in the rightmost side of the above-described [Equation 2].
The power adding operator 107 performs the power adding operation of the in-phase component correlation result from the adder 105xe2x80x2 and the quadrature component correlation result from the adder 106xe2x80x2, and outputs a final correlating operation result.
For the operation in the conventional matched filter, in each of the correlating operators 101xe2x80x2, 102xe2x80x2, 103xe2x80x2, 104xe2x80x2, the components of the received complex signal TX successively time-shifted and held in the data register 111xe2x80x2 or the like, and the components of the received code sequence C* successively time-shifted and held in the received code register 112 or the like are multiplied/operated in the multipliers 113xe2x80x2 or the like, and the multiplication results are added in the adder 114xe2x80x2 or the like, so that each correlation result is outputted.
Subsequently, the correlation results from the correlating operators 101xe2x80x2, 102xe2x80x2 are added as the in-phase components by the adder 105xe2x80x2, the correlation results from the correlating operators 103xe2x80x2, 104xe2x80x2 are added (subtracted) as the quadrature components by the adder 106xe2x80x2, the correlation results of the in-phase and quadrature components are subjected to the power adding operation by the power adding operator 107, and a final correlating operation result is outputted, so that the selection of the received code sequence and the detection of the path are performed based on the output.
When the matched filter is used in the correlator, the received complex signals and received code sequence can be accumulated for a certain time. Therefore, even when the transmission timing of the transmitter, that is, the path timing is not known, by inputting the received complex signals to the data register 111xe2x80x2, and the like while holding a certain series of codes, it can be judged in at least one series of time whether the selected received code sequence and transmitted code sequence agree with each other.
Moreover, when the selected received code sequence and transmitted code sequence agree with each other, a large power adding operation result is outputted at a certain timing, so that the path detection can be realized as described above.
In the above-described conventional matched filter, however, the received complex signals and received code sequence are held for a certain time, and the multiplication in each time series, and the addition of the multiplication results are performed, so that the hard scale is remarkably enlarged. Moreover, when the correlating operation of QPSK-modulated received complex signals is performed, four correlating operators (101xe2x80x2 to 104xe2x80x2) need to be disposed from this nature, which causes a problem that the circuit scale becomes huge.
Therefore, in order to reduce the hard scale of each of the correlating operators 101xe2x80x2 to 104xe2x80x2 in FIG. 6, a method is proposed which comprises reducing the number of bits of each multiplier 113xe2x80x2 disposed inside, and the like to decrease the number of bits of each adder 114xe2x80x2, in-phase component adder 105xe2x80x2, and quadrature component adder 106xe2x80x2, so that the hard scale is reduced.
Since the received code sequence are held in the code register 112, and the like in one bit of time series, in order to decrease the number of bits of the multipliers 113xe2x80x2, and the like, the number of bits of the data register 111xe2x80x2, and the like is decreased, so that as a result, the number of bits of the multipliers 113xe2x80x2, and the like is decreased.
Here, a matched filter constituted to reduce the circuit scale of the conventional matched filter shown in FIG. 6 will be described with reference to FIG. 7. FIG. 7 is a block diagram of the matched filter constituted to reduce the circuit scale of the conventional matched filter.
As shown in FIG. 7, the matched filter constituted to reduce the circuit scale of the conventional matched filter is provided with four correlating operators 101xe2x80x3, 102xe2x80x3, 103xe2x80x3, 104xe2x80x3, two adders 105xe2x80x3, 106xe2x80x3, and a power adding operator 107, which are constituted in the same manner as in the conventional matched filter shown in FIG. 6, and is additionally provided with characteristic portions of binary converting units 109-I, 109-Q.
Here, the binary converting unit 109 binarizes the received complex signal and outputs one bit of data to the correlating operator, the binary converting unit 109-I binarizes the in-phase component of the received complex signal, and the binary converting unit 109-Q binarizes the quadrature component of the received complex signal.
Specifically, the binary converting unit 109 quantizes the received complex signal with A/D converter, and the like, converts the signal to digital data, takes its most significant bit (MSB), or performs binarizing otherwise.
In the matched filter of FIG. 7, the received complex signal is one-bit binarized (xe2x80x9c0xe2x80x9d, xe2x80x9c1xe2x80x9d) and inputted to the correlating operator 111xe2x80x3, and the like. For example, when xe2x80x9c0xe2x80x9d as decimal xe2x88x921, or xe2x80x9c1xe2x80x9d as decimal +1 is multiplied by the received code sequence (xe2x80x9c0xe2x80x9d is defined as xe2x88x921, and xe2x80x9c1xe2x80x9d is defined as +1 in the same manner), as a result, +1 or xe2x88x921 is obtained in decimal notation.
This multiplication result can be represented as xe2x80x9c11xe2x80x9d, xe2x80x9c01xe2x80x9d in binary notation, and in order to perform the addition of multiplication results, the two-bit adders 114xe2x80x3, 105xe2x80x3, 106xe2x80x3 may be prepared as a result.
In the operation of the matched filter of FIG. 7, the components of the received complex signal TX are binarized by the binary converting unit 109 and converted to one bit of data, successively time-shifted and held in the data register 111xe2x80x2, and the like. The subsequent operation is the same as that of the conventional matched filter.
However, in the matched filter shown in FIG. 7, since the data inputted to the data register 111xe2x80x3 or the like is of one bit, each shift register constituting the data register 111xe2x80x3 or the like may be a register of one bit. Furthermore, since the data inputted to each multiplier 113xe2x80x3 or the like is of one bit, each multiplier 113xe2x80x3 or other constitution is reduced. Additionally, when the number of bits outputted from each multiplier 113xe2x80x3 or the like decreases, the number of input bits of the adders 114xe2x80x3, 105xe2x80x3, 106xe2x80x3 decreases. Therefore, the circuit scale of each adder is reduced, and as a result the entire circuit scale of the matched filter is reduced.
In the matched filter of FIG. 7, the circuit scales of the multiplier 113xe2x80x3 and adders 114xe2x80x3, 105xe2x80x3, 106xe2x80x3 are reduced by binarizing the inputted received complex signal, and as a result the entire circuit scale is reduced, but different from the correlating operation of the n-bit accuracy data register 111xe2x80x2 to the code register 112 in the conventional matched filter of FIG. 6, the correlating operation of one bit accuracy to the code register 112 is performed, which lowers the operation accuracy and which causes a problem that the sensitivities in code determination and path selection are deteriorated.
The present invention has been developed in consideration of the above-described actual circumstances, and an object thereof is to provide a correlating operation method and a matched filter which can reduce the circuit scale without deteriorating sensitivities in the selection of received code sequence and the detection of paths.
According to the present invention, there is provided a correlating operation method, comprising: performing correlating operation of code data obtained by adding or subtracting an in-phase component and a quadrature component of a received code sequence, and an in-phase component and a quadrature component of a received complex signal; and performing power adding operation of an in-phase component correlation result and a quadrature component correlation result to obtain a correlating operation output, in which a section for performing the correlating operation of the received code sequence and the received complex signal can be realized by two sections, so that circuit scale is reduced, and power consumption can be curtailed.
According to another aspect of the present invention, there is provided a correlating operation method, comprising: inputting an in-phase component and a quadrature component of a received code sequence, and ternary-converting and inputting an in-phase component and a quadrature component of a received complex signal;
performing a first correlating operation of the ternary-converted in-phase component of the received complex signal and the in-phase component of the received code sequence, a second correlating operation of the ternary-converted quadrature component of the received complex signal and the quadrature component of the received code sequence, a third correlating operation of the ternary-converted quadrature component of the received complex signal and the in-phase component of the received code sequence, and a fourth correlating operation of the ternary-converted in-phase component of the received complex signal and the quadrature component of the received code sequence;
adding results of the first and second correlating operations to output an in-phase component correlation result, and adding results of the third and fourth correlating operations to output a quadrature component correlation result; and
performing power adding operation of the in-phase component correlation result and the quadrature component correlation result to obtain a correlating operation output. The components of the received complex signal are ternary-converted, and the number of bits is reduced, before taking, shifting, accumulating, further multiplying and adding the components. Therefore, as compared with the matched filter in which the constitution of the multiplying section and multiplication result adding section during the correlating operation is reduced and the components of the received complex signal are binary-converted and taken, the sensitivities in the selection of the received code sequence and the detection of the path can be held to some degrees.
According to further aspect of the present invention, there is provided a matched filter, comprising: an adding/subtracting unit for adding or subtracting an in-phase component and a quadrature component of a received code sequence to output code data; an in-phase component multiplying unit for multiplying in-phase component data obtained by successively time-shifting the in-phase component of the received complex signal and the code data outputted from the adding/subtracting unit; a quadrature component multiplying unit for multiplying quadrature component data obtained by successively time-shifting the quadrature component of the received complex signal and the code data outputted from the adding/subtracting unit; an in-phase component adding unit for adding the output from the in-phase component multiplying unit to output an in-phase component correlation result; a quadrature component adding unit for adding the output from the quadrature component multiplying unit to output a quadrature component correlation result; and a power adding operation unit for performing power adding operation of the in-phase component correlation result and the quadrature component correlation result to output a correlating operation result, in which the section for performing the correlating operation of the received code sequence and the received complex signal can be realized by two sections, the circuit scale is reduced, and the power consumption can be curtailed.
According to still another aspect of the present invention, there is provided a matched filter, comprising: ternary-converting an in-phase component and a quadrature component of a received complex signal; performing correlating operation with code data obtained by adding or subtracting an in-phase component and a quadrature component of a received code sequence; and performing power adding operation of correlation results of the in-phase component and the quadrature component to obtain a correlating operation output, in which the section for performing the correlating operation of the received code sequence and the received complex signal can be realized by two sections. Furthermore, by ternary-converting the components of the received complex signal, and reducing the number of bits before taking the components, the sensitivities in the selection of the received code sequence and the detection of the path are held to some degrees, while the constitution of the correlating operation section can further be reduced.

Correlation operation method and matched filter


A motion sensing device for sensing infrared rays includes a substrate; an optical module, including a first spacer layer, coupled to the substrate; a first glass layer, formed on the first spacer layer; a second spacer layer, formed on the first glass layer; a second glass layer, formed on the second spacer layer; a third spacer layer, formed on the second glass layer; a first lens, bonding on a first side of the second glass layer; and a second layer, bonding on a second side relative to the first side of the second glass layer; and a coating layer, covered on the optical layer for shielding the infrared rays, wherein the coating layer does not cover the first lens.

1. Field of the Invention
The present invention relates to a motion sensing device, and more particularly, to a motion sensing device realized by a wafer level lens.
2. Description of the Prior Art
With the scientific and technological advancement, computer systems are viewed as necessities for ordinary people in their daily lives, from traditional functions, such as word processing and program executing, to modern multimedia processing, and computer games, etc. Thus, technology of the input apparatus also has improved.
A pointing device is utilized for transforming motions of a user into signals via a motion sensor capable of sensing a motion trace for an electronic device having computing capacity, so as to control the movement of graphical cursers or pointers on display screens, to select objects on display screens with a graphical user interface, and to perform control functions displayed on the screen, allowing the user direct interaction with the computer system. Thus, how to realize the motion sensor with high accuracy becomes a topic to be discussed.


An in-tank type fuel pump which can easily be installed and reduces the vibration caused by the fuel pump. The fuel pumped up by a pump part passes through a filter to have foreign matter contained therein removed. Then, the fuel flows from a fuel passage, through an opening part in a cap, into a recessed part and a second fuel passage. The fuel that has flowed into the second fuel passage lifts a check valve and flows into the recessed part. Then, the fuel flows through a third fuel passage to a discharge pipe, and then is guided to the outside of the fuel tank. A ball moves within a large-diameter passage according to the fuel pressure to regulate the fuel pressure required for fuel injection. When the fuel pumping is ceased, the fuel pressure falls to 0, and therefore the ball is forced to contact a valve seat by the spring force of a compression coil spring. Then, the head part of the check valve is forced to contact a valve seat to block the fuel passage. As a result, the residual fuel pressure can be maintained downstream from the recessed part.

1. Field of the Invention:
The present invention generally relates to a fuel supply device. More particularly, the present invention relates to a fuel supply device that supplies fuel from a fuel tank to a fuel consumption device, such as an internal combustion engine.
2. Related Art:
A system is known in which fuel pressure is maintained at a constant level by a pressure regulator. The fuel is atomized and supplied to an internal combustion engine under the controlled pressure. In this system, excess fuel resulting from fuel pressure control is returned to the fuel tank.
U.S. Pat. Nos. 5,044,344, 5,148,792, and 5,078,167 disclose a system that supplies all the fuel from a fuel tank to an internal combustion engine by means of pressure feeding. Such a system has no return route. In the system disclosed in the U.S. Pat. Nos. 5,044,344 and 5,148,792, the ability of a fuel pump is fed back and controlled according to the pressure detected by a pressure sensor. Further, a relief valve is provided in a fuel supply route to protect the fuel from excessive pressurization. However, such a fully and electronically controlled system as the above is expensive.
In contrast with such a fully and electronically controlled system, a less expensive system can be achieved by providing a pressure regulator within the fuel tank, as is disclosed in U.S. Pat. No. 5,078,167. Furthermore, even with the pressure regulator provided in the fuel tank, electronic control can also be used to reduce surplus fuel quantity discharged by the pressure regulator and save wasteful power consumption.
In such a conventional fuel supply device, however, a terminal disposed on the wall of the fuel tank is connected to the fuel pump disposed within the fuel tank via rubber piping. This type of fuel pump requires a considerable number of man-hours to install, which increases manufacturing cost.
Also, in the systems discussed above, as a check valve, a relief valve and/or a pressure regulator for preventing excessive high pressure, a projected part of the terminal is disposed on the wall of the fuel tank. Such a structure includes the problem where the shape around the discharge part of the main body of the fuel pump has to be modified. Further, due to the uniqueness of the systems, it is difficult to share many parts and components with many other fuel supply systems.
Furthermore, in the system disclosed in U.S. Pat. No. 5,078,167, the temperature of the fuel in the fuel supply route rises while the fuel pump is at a stoppage, and when the fuel pressure rises, the pressure regulator opens to lower the fuel pressure. This causes the problems of a decreasing quantity of fuel in the fuel supply route as time passes, air bubbles become mixed in the fuel or fuel vapor is generated, and as a result, when the fuel pump is restarted, fuel containing air bubbles or fuel vapor is supplied to the internal combustion engine. Such is not conducive to efficient operation of the internal combustion engine.


A method for manufacturing an airtight, recyclable, biodegradable package includes the steps of stamping a cardboard sheet to mark the folding lines which define the lateral walls, the top walls and the bottom of the package as well as adhesive bands. The sheet is then sterilized. A fast drying adhesive substance is applied on the adhesive bands between the walls. The cardboard sheet is then folded so that the adhesive bands overlap each other in pairs forming a tube. The ends of the tube are closed by folding the bottom walls making a flat base. The top walls are folded to seal the tube. The adhesive in the adhesive bands becomes activated to form a closed airtight package.

This invention relates to the means used in the manufacturing of airtight packaging in general, and more specifically it relates to a method for the manufacturing of an airtight package which is not only recyclable but also biodegradable.
Sachets are widely used in order to pack all kinds of consumer products. Said sachets are a tube-shaped waterproof bag, closed by cross stitching in both its ends.
This kind of packaging, although it is low-cost, poses a series of problems and drawbacks. It may be easily punctured or damaged; stacking is extremely difficult due to its shape; it can not stand on its base, and this, in turn, makes handling difficult.
Similarly, multilayer-packaging is also widely used. Multilayer-packaging consists of a cardboard piece (a) lined by layers made of either aluminium or plastic, or other materials.
Contrary to the former, this kind of packaging, can hold all sorts of products, keeping them in excellent conditions and at relatively low cost.
Moreover, in the case of consumer foods, this kind of packaging is resistant enough, easy to open and easy to use when serving (as the folded lugs in its top wall have a funnel-like shape when open). Furthermore, the material it is made of guarantees an airtight closing; it is not polluting, and neither the nutritional properties of the foods packed in them nor the taste thereof will ever be affected.
On the other hand, another advantage of this kind of packaging, is that it is prismatic and rectangular, which not only remarkably enables the handling thereof but also allows it to stand safely on its flat base, and makes stacking easier even if storage space is limited or small.
However, the above mentioned multilayer packaging poses a serious drawback, which in the light of the current ecological trends and guidelines towards preservation, should be taken into account.
In fact, as this packaging consists of aluminium sheets and plastic layers, once it is used it can not be recycled, and most important of all, it is not biodegradable.
The aforesaid means that, although this kind of packaging has contributed significantly, it is a real polluting factor, specially due to the fact that, as it is used for mass consumption products, it becomes a part of the huge mass of pollutants which contaminate the soils, the environment, and is impossible to dispose of.
The invention that this description relates to has solved all these drawbacks in a very easy and ingenious way, since this package embodies all the advantages of the others, but apart from that is not polluting, it is both recyclable and biodegradable.
Because of this, it is reasonable to predict how successful this invention will turn out to be, irrespective of the category or use it may have, as it can be used for the packaging of any kind of solid products, granules or dusts etc.

Method for the manufacturing of an airtight, recyclable and biodegradable package


A system for opening and closing an elevator door panel utilizes a linkage which attaches a belt to the panel. The system is further characterized by a first portion of the belt having a first end and a second end, a housing for holding the first end in close proximity to the second end, and a second portion of the belt which is aligned in register with the first and second ends of the first portion. The second portion is clamped against the first and second ends of the first portion and against the housing so that the first portion of the belt forms a continuous shape.

Some elevator door operating systems consist of a reversible motor, a belt, a speed reducing pulley, a transmission pulley, an idler pulley, and a continuous toothed belt. The motor transmits torque via the belt to the speed reducing pulley. The speed reducing pulley is attached to the transmission pulley. The cog belt, which extends around the transmission and idler pulleys, is driven by the transmission pulley. A portion of the cog belt travels linearly between the transmission pulley and the idler pulley. The linear motion of the cog belt is transmitted to each car door panel by means of a linkage.


A method and unit for easily and continuously producing high pressure gaseous monosilane and high pressure liquid monosilane, each having an ultra high purity. In the ultra high purity monosilane producing method, a feed monosilane gas is pressurized, cooled down and subjected to a gas-liquid phase separation. The separated gas phase is introduced to a lower rectification column 1 so as to be rectified. The gas obtained through this rectification is introduced to an upper rectification column 2 so as to be rectified, wherein a gaseous monosilane product or liquid monosilane product having an ultra high purity is taken out of the bottom portion of the upper rectification column.

Monosilane gas is generally indispensable for the manufacture of ultra LSIs, solar batteries, photosensitive materials and the like.
A known method for producing monosilane gas is that disclosed in the official gazette of Japanese Patent Publication No. 3,806/1989.
Such monosilane gas preferably should have a high purity, for instance, of 99.9999% or more. However, a preferred method for producing such high purity monosilane gas and a preferred unit therefor have not yet been developed.
The present invention is intended to achieve the aforementioned purpose.

Method of producing ultra high purity monosilane and apparatus therefor

L'air Liquide, Societe Anonyme Pour L'Etude Et L'Exploitation Des Procedes Georges Claude


A semiconductor device and a method of forming the same are disclosed. The semiconductor device includes a substrate, and a source region and a drain region formed in the substrate. The semiconductor device further includes an impurity diffusion stop layer formed in a recess of the substrate between the source region and the drain region, wherein the impurity diffusion stop layer covers bottom and sidewalls of the recess. The semiconductor device further includes a channel layer formed over the impurity diffusion stop layer and in the recess, and a gate stack formed over the channel layer.

The semiconductor integrated circuit (IC) industry has experienced exponential growth. Technological advances in IC materials and design have produced generations of ICs where each generation has smaller and more complex circuits than the previous generation. In the course of IC evolution, functional density (i.e., the number of interconnected devices per chip area) has generally increased while geometry size (i.e., the smallest component (or line) that can be created using a fabrication process) has decreased. This scaling down process generally provides benefits by increasing production efficiency and lowering associated costs. Such scaling down has also increased the complexity of processing and manufacturing ICs.
For example, carrier mobility is an important concern for the performance of a transistor, such as a metal oxide field effect transistor (MOSFET). With its decreased size, a transistor also has a decreased channel length, making it easier for impurities from source and drain regions of the transistor to diffuse into its channel region. Such impurities consequently reduce mobility of the carriers within the channel region. This is particularly troublesome with p-type MOSFETs where boron is usually the dopant in the source and drain regions because boron has a lower atomic weight and longer diffusing length than other commonly used dopants, such as phosphorus, in n-type MOSFETs. Furthermore, it has been observed that there are higher variations in ion implantation depth with smaller transistors. This contributes to higher variations in both carrier mobility and threshold voltage (Vt) of such transistors, adversely affecting their performance.

Structure and method for semiconductor device

TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD.


Capillary flow liquid transfer device having first and second flow channels, the first leading from a first channel end to a volume determination site and the second flow channel leading from a second channel end and crossing the first channel in fluid connection therewith in an interception area bordering the volume determination site directly upstream thereof relative to the flow in the first channel. The liquid flow in the second channel reaches the interception area before that in the first channel upon simultaneous application of liquid from the liquid supply to the first and second channel ends such that excess substance is received in a waste reception area separate from substance received in the volume determination site.

A number of such devices for manual operation have been developed in recent years, these being designed to avoid any need for complex procedures, and thus be suitable for use by lay persons. For example, to avoid the necessity of a timed sequence of reagent additions to an analyte, devices have been developed to automatically sequentially deliver such reagents by use of multiple capillary flow channels. Examples of these capillary flow diagnostic devices are further described in Patent Specification WO90/11519 and in co-pending UK Patent Applications GB-2261283 and GB-2261284.
In some applications of devices of this type a user is looking for a simple colour change to confirm the presence of a specific analyte in a sample. In others, the user may be seeking a quantified result such as a certain degree of colour change, and it is in these latter applications that a need arises to accurately measure out, or define, a desired volume of the sample onto the device.
Currently, the sample volume is measured out and applied to an analytical site of the diagnostic device, the analytical site comprising a quantity of antibodies immobilised within a specific region. The volume measuring is done using a hand pipette or capillary tube. Pipettes are expensive precision instruments and considerable skill is needed to achieve accurate results. Capillary tubes are less expensive, and may include a porous plug to define the sample volume. However, they are usually made of glass and therefore readily breakable in mass usage, and in any case an inexperienced user can find them difficult to use.
If an undefined amount of sample is applied to an analytical site, then there may well be an `error volume` of sample deposited beyond the boundaries of the immobilised region. This is in general terms unlikely to create a major inaccuracy with respect to sample lying downstream or laterally of the immobilised region, but error sample lying upstream of the immobilised region will be passed by liquid flow through the region and there may be reaction between the antigen of interest contained therein and the antibodies at the analytical site, thus ultimately leading to an inaccurate result.
One known method of sample volume definition is to incorporate a manually operated valve mechanism, which shears off a defined volume of sample in;to the diagnostic device. Such a device is described in M. P. Allen et al, Clinical Chemistry 36 (1990) p.1591-1597. The measuring out of sample volume is thus automatically realised and possibilities for error are thus greatly reduced. However, the mechanism involves precision moving parts and is thus relatively expensive to manufacture.

Capillary flow liquid transfer device having waste reception area


A system for measuring properties of a medium includes an electromagnetic generator for forming a CW carrier, a digital encoder for forming a digital message, and a modulator for modulating the CW carrier with the digital message to form a digitally modulated CW carrier. The medium provides a channel for propagating the digitally modulated CW carrier. The system further includes a receiver configured to receive the propagated, digitally modulated CW carrier, and a processor for measuring at least one property of the medium. The medium may be disposed within a gaseous atmosphere, a body of water, or a cell of a laboratory.

Active remote sensing may be conceptualized as viewing radiation reflected and/or emitted from a certain location in one or more wavelength regions. Active remote sensing typically utilizes one or more sources of radiation (e.g., infrared, visible, or ultraviolet light) to illuminate a target area while measuring the reflected, scattered and/or emitted radiation at one or more receive detectors. Such remote sensing may be performed from a moving platform or from a stationary location, each of which may be spatially remote from the target area.
One method for performing active remote sensing is to stare at an area with a single detector, while illuminating the area with one or more wavelengths of radiation. Various sources of noise, however, may lower the signal-to-noise ratio (SNR) of the measurement. Examples of such noise typically present in active remote sensing include solar background radiation, 1/f noise (i.e., noise whose power varies inversely with frequency), atmospheric turbulence, and/or scintillation, and noise from varying reflectivity.
Thus, there is a need in the art to perform active remote sensing, using compact efficient transmitters and compact receivers while maintaining a high signal-to-noise ratio.

Method and system for measuring optical properties of a medium using digital communication processing techniques


A thin-film transistor having a protection layer for a planarization layer. The protection layer prevents reduction of the planarization layer during an ashing process, thereby preventing the formation of a steeply tapered via hole through the planarization layer. In this manner, the via hole may be coated with a conductive element that may serve as a conductive path between a common electrode and the drain of the transistor.

Multi-step mask process flows may be used to manufacture thin-film transistor devices, including thin-film transistors that operate pixels in an electronic display. Pixel thin-film transistors may include a common voltage electrode. This common voltage electrode (VCOM electrode) may have a relatively high sheet resistance, which is undesirable.
Accordingly, some pixel thin-film transistors employ a third metal layer to reduce the sheet resistance of the VCOM electrode. (Generally, the first and second metal layers correspond to the gate and source/drain of the transistor.) The implementation of a third metal layer may add an additional mask to the process flow, thereby increasing the cost of manufacture and reducing the manufacturing yield. Generally, any increase in the number of masks required to create a transistor has an adverse effect on manufacturing.
The number of masks may be reduced by using a halftone process etch both the common electrode and third metal. However, such a halftone process may result in a loss of thickness in the planarization layer during an ashing process used to remove the photoresist that forms the halftone. This may result in, ultimately, a mis-formed via hole between a pixel conductive upper layer and the source/drain or gate metal. Thus, it may be desirable to protect the planarization layer during manufacturing.

Protection layer for halftone process of third metal


A primary radiation diaphragm for a radiation apparatus has at least one diaphragm plate which is adjusted in a plane extending perpendicular relative to the central ray of radiation. Each plate is provided with a single mount which engages a guideway disposed on the wall of the housing. Preferably, four plates are arranged in two pairs, with the first pair lying in a first plane and the second pair lying in a second plane extending parallel to the first pair, each of the plates of the pair has a single mount and the pair of plates of the first pair engage the same guideway, while the pair of the second plate engage a second guideway disposed on a wall of the housing extending at right angles to the first-mentioned wall.

The present invention is directed to a primary radiation diaphragm for a radiation apparatus. The diaphragm comprises at least one diaphragm plate adjustable in a plane perpendicular relative to the axis of the central ray of the radiation transmitter or emitter.
U.S. Pat. No. 4,691,335, whose disclosure is incorporated herein by reference thereto and which claims priority from German Application 84 36 281(U), as well as German Published Application 14 41 312, disclose primary radiation diaphragms wherein two diaphragm plate pairs are respectively oppositely adjustable relative to one another in two parallel planes so that a rectangular gating of the x-ray beam is possible. The adjustment of the diaphragm plates lying above one another must, therefore, occur in such a way that only the opening that defines the radiation field is left free. The diaphragm plates are adjustably seated by, respectively, two mounts provided on sides lying opposite one another.

Primary radiation diaphragm for a radiation apparatus


A malleable implant for implantation into living tissue is prepared having access means for cells into the interior of the implant. The implant is capable of being deformed under pressure required to insert the implant into an implant site. The access means can be hollow or solid. The solid comprises a material that more rapidly resorbs in vivo than the malleable implant to provide channels, or comprises a mechanically weak material that fractures under force at an implant site to produce channels or cracks. The access means may be inserted in the malleable implant at an implant site. A multilaminar structure may be formed having layers of malleable implant and layers of access means, or the access means may be heterogeneously distributed throughout the malleable implant. A kit can contain a powder such as calcium phosphate for making a paste implant material, and an access means insertable into the paste.

This invention relates to implant materials having access channels for enhanced cell-mediated resorption of the implant into living tissue. This invention also relates to materials for the cell-mediated remodeling of an implant.
Damage to body tissue often requires the use of an implant material to replace, support or repair the damaged tissue. For example, implants may be used in the repair of bone fractures or periodontal defects, replacement of damaged cartilage and soft tissues such as muscle tissue and collagen.
In the case of fracture, disease or other injury to bone, proper healing and bone remodeling depends on the successful stabilization of the bone site and the ability to induce bone regeneration and repair. In the instances where damage to the bone is large, a bone graft material (implant) may be introduced into the bone site to bridge the gap left by the damaged bone in order to fill open spaces and prevent fibrous ingrowth into the defect, as well as to aid in the stabilization of the fracture. Often times a resorbable bone graft material is selected to serve this function. Both biologically derived materials such as autographs and allografts, as well as synthetic glasses, calcium phosphates and calcium sulfates, are examples of resorbable bone graft materials.
A variety of synthetic bone implants have been shown to be resorbed or partially resorbed by host cells. Cells which are recognized as important in the resorption process include osteoclasts, osteoblasts, macrophages and vascularizing elements. Since these cells necessarily gain access to the implant by way of the surface, specific surface characteristics may significantly affect remodeling and resorption rates. For example, the ratio of implant surface area to implant volume is expected to have significant ramifications on implant resorption and remodeling rates by cells.
A variety of materials have been proposed for use as bone implant materials, including porous metals, biodegradable organic polymers, and ceramic materials. The use of calcium phosphate materials as implants in bone sites is known. Calcium phosphate cements represent biocompatible materials which provide the components necessary for the formation of bone, namely, calcium and phosphate ions, and which may act as a substrate for bone growth, i.e., they are osteoconductive.
Materials for use as implants range from substantially non-resorbable materials, i.e., porous metals, bioglass and corraline, to highly resorbable materials, i.e., selected organic polymers, calcium phosphates, and composites thereof. In most applications, it is desirable to have materials which are highly resorbable, and which can be replaced by living tissue in a short time period. Furthermore, the implant material ideally is capable of being formed into complex shapes that fit the contours of the repair site. An accurately contoured implant will enhance the integration of natural tissue at the site.
Calcium phosphate cements are known, which set rapidly at room and/or body temperature. See, U.S. Pat. Nos. 5,522,893, 5,525,148, RE 33,161 and RE 33,221 to Chow et al, U.S. Pat. No. 5,605,713 to Boltong et al. and U.S. Pat. No. 5,336,264 to Constantz et al. Such cements provide the ability to form complex shapes with intimate host bone contact, however, the osteoconductivity and the remodeling capability of the resulting material may often be less than desired.
Lee et al. in U.S. Pat. Nos. 5,683,461 and 5,783,217 describe a bioresorbable calcium phosphate cement which is an excellent osteoconductive substrate. The calcium phosphate implant is resorbed in as little as 3-12 weeks in small animal models, and bone tissue substantially similar to naturally occurring bone is formed in its place. Even in these calcium phosphate cements, the remodeling capability sometimes is less than ideal, particularly when they are used to produce large volume implants.
Porosigens have been used to increase porosity in materials. Porosigens include additives, usually particulate in nature, which are leached out or dissolved to form pores or voids which increase the porosity of the implant. While porosigens have been associated with increased resorbability, known porosigens do not provide adequate access to the interior of the implant on a scale sufficient to permit cell-mediated resorption or remodeling of the implant.
Chow et al in U.S. Pat. No. 5,525,148 report the use of pore-forming agents to create pores sufficiently large to cause vascularization of tissue which infiltrates the cement once placed in the body. Chow reports the addition of particulate additives such as sugars, sodium bicarbonate or phosphate salts, which are removed by resorption into the body tissue, dissolution in physiological fluids, or heating after the cement has hardened (presumably before implantation). Due to the nature of the particulate additive, the pores are on the micron or submicron scale, i.e., xe2x80x9cnon-macroxe2x80x9d scale, and the internal porosity remaining after the porosigen is removed is random and often non-continuous.
Solid ceramic implants have been prepared in a variety of sizes and shapes.
Johnson et al. in WO 99/16479, entitled xe2x80x9cBone Substitute Materialsxe2x80x9d, describe a hard, open ceramic framework as a bone implant material. The porous structure is obtained by coating an open-celled organic material with a ceramic oxide and then sintering to burn out the open-celled material.
Boyan et al. in U.S. Pat. No. 5,492,687, entitled xe2x80x9cBiodegradable Implant for Fracture Nonunions,xe2x80x9d describe a substitute bone graft material having interconnected pores and canals having the size, shape and spacing corresponding to Haversian canals, i.e., naturally occurring canals of cortical bone which allow vascularization. The implant is formed by casting a polymeric gel into the desired shape, including channels, and drying to form a solid implant.
In the above examples, the implant is a solid structure in which the porous substructure is introduced into the material prior to implant. Such implant structures are not moldable or able to form complex shapes with intimate host bone contact.
There remains a need to provide an implant material and methodology, in which access into the interior of the implant material is provided, while retaining the host-conforming ability of a paste or putty.
Furthermore, there remains a need to increase the rate and level of cellular ingress into the implant so that the remodeling rate and efficiency of implant material is enhanced.
There remains a need for providing greater access to cells of living tissue to the interior of an implant material to increase implant resorption and tissue remodeling.
The present invention provides means for cellular access into the interior of a malleable implant to optimize cell contact with the implant material. The access means is a macrostructure that provides access to the interior of a soft, conformable implant material, which upon hardening provides a structural access channel for cells to the interior of the implant.
In one aspect, the inventive implant includes a malleable implant material, and a non-particulate access means for providing macroscopic access into the interior of the implant to cells of the living tissue.
In preferred embodiments, the implant has at least one cross-sectional dimension of greater than 3 mm, and preferably at least one cross-sectional dimension of greater than 1 cm.
In other preferred embodiments, the malleable implant material is comprised of a bioresorbable material and a physiologically acceptable fluid. The malleable material is selected from the group consisting of calcium phosphates, collagens, and fibrins. In one embodiment, the malleable implant material is hardenable, or the malleable implant material is an osteoconductive material.
In one embodiment, the calcium phosphate is selected from the group consisting of amorphous calcium phosphate, tricalcium phosphate, hydroxyapatite, calcium deficient hydroxyapatite, poorly crystalline hydroxyapatite (PCHA), calcium deficient hydroxyapatite, dicalcium phosphate dihydrate (DCPD), tetracalcium phosphate, and dablite (Ca5(PO4,CO3)3F).
In a preferred embodiment, the non-particulate access means is selected from the group consisting of tubes, rods, fibers, sheets, star-shapes, jack-shapes, fibrous mats, and complex structures. The non-particulate access means may be hollow and open at at least one end and contactable with living tissue, and having an inner diameter of a size which permits access by cells of the living tissue. The non-particulate access means may be solid, having at least one end contactable with living tissue, and having an outer diameter of a size which permits access by cells of the living tissue. In one embodiment, the non-particulate access means is non-resorbable, and may be selected from the group consisting of sintered ceramics, poly(methylmethacrylate), and high molecular weight polyethylene. In other embodiments, the non-resorbable non-particulate access means is positioned and arranged so that the macrostructure terminates in the interior of the implant.
In one embodiment, the non-particulate access means is resorbable, and may be selected from the group consisting of poly(lactide), poly(lactide-co-glycolide), gelatins, collagen, alginate, tissue culture medium, calcium phosphates, calcium sulfate, sugars, carbohydrates, and salts. The non-particulate access means includes a material resorbable by dissolution, enzymatic or cellular action to provide cellular access to the interior of the implant, and preferably includes a nutrient of a cell of the living tissue.
In other embodiments, the non-particulate access means includes a polymer capable of acting as a substrate for cell attachment, and further may include a material for promoting cell adhesion.
In preferred embodiments, the non-particulate access means has a dimension greater than 0.5 mm, and preferably a dimension greater than 1 mm, and more preferably greater than 5.0 mm.
In other preferred embodiments, the non-particulate access means is insertable into the malleable implant material at an implant site. In one embodiment, the implant is a multilaminar structure having layers of malleable implant material and non-particulate access means. In other embodiments, the non-particulate access means is heterogeneously distributed throughout the implant.
In other preferred embodiments, the non-particulate access means includes a mechanically weak material susceptible to fracture at an implant site thereby resulting in channels or cracks, and may be selected from the group consisting of hydrogels, oils, lipids, lubricants, sugars and salts.
In one embodiment, the inventive implant further includes additives capable of controlling the resorption rate of the implant material, and may be selected from the group consisting of bone morphogenic protein, OP-1 parathyroid hormone, parathyroid-hormone-related peptide, 1,25-dihydroxyvitamin D, interleukin-1, tumor necrosis factor, thyroid hormones, vitamin A, transforming growth factor/epidermal growth factor, fibroblast growth factor, heparin, bacterial endotoxin, thrombin, bradykinin, prostaglandin E2 and other protanoids, transforming growth factor xcex2, lymphocyte inhibitory factor/differentiation inducing factor, calcitonin and related peptides, interferon-xcex3, glucocortinoids, estrogens and androgens.
In another embodiment, the inventive implant further includes reinforcing additives.
In another aspect of the invention, a kit is provided having a powder for use in preparing a paste, and a macrostructure insertable into a paste, said macrostructure providing access to a cell to the interior of the paste. In preferred embodiments, the powder includes a calcium phosphate. In other preferred embodiments, the kit further includes a mixing pouch, or a physiologically acceptable fluid.
In yet another aspect of the invention, a method of enhancing remodeling at an implant site is provided. The method includes the steps of implanting a malleable implant material at a host site and, before or after the step of implantation, introducing non-particulate access means into the malleable implant material for providing macroscopic access into the interior of the implant material to cells of the host, whereby cells of the host are introduced into the interior of the implant material. In preferred embodiments, the access means are introduced after implantation.
In one embodiment, host cells preferentially act upon the access means to degrade and thereby remove the access means to create a conduit within the implant.
In preferred embodiments, the method includes an implant having at least one cross-sectional dimension of greater than 3 mm, and preferably at least one cross-sectional dimension of greater than 1 cm.
In other preferred embodiments, the method includes a malleable implant material comprised of a bioresorbable material and a physiologically acceptable fluid, and the malleable implant material may be hardenable or it may be an osteoconductive material, such as calcium phosphates, collagens, and fibrins.
In other embodiments, the calcium phosphate is selected from the group consisting of amorphous calcium phosphate, tricalcium phosphate, hydroxyapatite, calcium deficient hydroxyapatite, poorly crystalline hydroxyapatite (PCHA), calcium deficient hydroxyapatite, dicalcium phosphate dihydrate (DCPD), tetracalcium phosphate, and dahlite (Ca5(PO4,CO3)3F).
In yet other embodiments, the method includes non-particulate access means selected from the group consisting of tubes, rods, fibers, sheets, star-shapes, jack-shapes, fibrous mats, and complex structures. It may be hollow and open at at least one end, contactable with living tissue, and having an inner diameter of a size which permits access by cells of the living tissue. It may be solid, having at least one end contactable with living tissue, and having an outer diameter of a size which permits access by cells of the living tissue.
In some embodiments, the method includes non-resorbable, non-particulate access means is non-resorbable, and may be positioned and arranged so that the macrostructure terminates in the interior of the implant.
In other embodiments the method includes resorbable, non-particulate access means and may be selected from the group consisting of poly(lactide), poly(lactide-co-glycolide), gelatins, collagen, alginate, tissue culture medium, calcium phosphates, calcium sulfate, sugars, carbohydrates, and salts. The non-particulate access means is comprised of a material resorbable by dissolution, enzymatic or cellular action to provide access to the interior of the implant. The non-particulate access means is comprised of a nutrient of a cell of the living tissue, or a polymer capable of acting as a substrate for cell attachment. The implant may further include a material for promoting cell adhesion.
In yet other embodiments, the method includes a non-particulate access means having a dimension greater than 0.5 mm, preferably greater than 1 mm, and more preferably greater than 5.0 mm.
In other embodiments, the non-particulate access means is inserted into the malleable implant material at an implant site, or it may be a multilaminar structure having layers of malleable implant material and non-particulate access means, or it may be heterogeneously distributed throughout the implant.
In other embodiments, the method includes a mechanically weak non-particulate access means susceptible to fracture at an implant site and a force is applied to the implant to thereby result in channels or cracks.
In still other embodiments, the implant may further include additives capable of controlling the resorption rate of the implant material, or reinforcing additives.
xe2x80x9cAccess meansxe2x80x9d is used herein to mean a structural element that is introduced into an implant material to provide cells access to the implant interior. The access means may provide such access either by providing empty conducts, voids or channels through which cells may pass, or by preferential resorbability or dissolution, or by preferential material failure which has the effect of introducing breaks, channels or other access pathways into the implant interior.
xe2x80x9cBiocompatiblexe2x80x9d means that the material does not elicit a substantial detrimental response in the host, such as for example, an immune response or an inflammatory response having a negative effect on the host. A material is considered biocompatible when the host responses are within medically acceptable ranges.
xe2x80x9cBioresorbablexe2x80x9d means the ability of a material to be resorbed or remodeled in vivo. The resorption process involves degradation and elimination of the original implant material through the action of body fluids, enzymes or cells. The resorbed materials may be used by the host in the formation of new tissue, or it may be otherwise re-utilized by the host, or it may be excreted.
xe2x80x9cCellular action or processxe2x80x9d involves an enzymatic or metabolic process carried out by a cell. The degradation and/or breakdown of the implant material resulting from the cellular process may be the result of enzymatic processes involving enzymes such as phosphatase which hydrolyzes phosphomonoesters (phosphates) or hydrolase which catalyzes the hydrolysis of a variety of bonds, such as esters, glycosides, peptides or by means of cell-mediated acidification as is known to occur during osteoclast resorption of bone.
xe2x80x9cImplant interiorxe2x80x9d is that portion of the implant which is not immediately accessible from the surface, or which is accessible to the surface only through an access channel and is some distance from the surface. Generally, as used herein implant interior refers to a portion of the implant which is, at the time of implantation, more than 5 mm from any surface, more than 2 mm and always 1 mm from the implant outer surface. Determination of distance from surfaces is not measured from any surface defining an access channel.
xe2x80x9cMacrostructurexe2x80x9d means a structure having dimensions on the order of millimeters or more. The macrostructure preferably has at least one cross-sectional dimension of at least 0.1 mm, and more preferably at least 1.0 mm. The dimension of the structure is selected to accommodate cells, blood vessels (vasculature) and other organelles needed to sustain the living tissue. Osteoclasts, which are a preferred cell for remodeling of bone, typically have diameters on the order of 0.1-0.3 millimeters. Vascularization generally requires even larger access dimensions to accommodate the multitude of capillaries formed in the vascularization process.
xe2x80x9cMalleablexe2x80x9d means capable of being shaped or deformed under pressure or other force. In the present invention, the pressure is applied in conjunction with introduction or insertion of channel makers into the malleable implant paste, or introduction of the malleable implant material into an implant site.
xe2x80x9cNon-particulatexe2x80x9d means a material that is not in a powder or a particulate form, that is, the material is not a powder, fragment, granule, grain or particle. However, the material may be comprised of particulate subcomponents which have been combined to form a larger unitary structure, such as can be obtained using powder compaction and powder pressing techniques. The non-particulate member has at least one cross-sectional dimension on the order of at least 0.1 mm, preferably at least 1 mm and more preferably at least 0.5 cm, and can range much higher, e.g. xcx9c5 cm, in some instances.
xe2x80x9cResorptionxe2x80x9d means the loss of substance (mass) through physiological means, such as those processes involved in loss of dentin and cementum of a tooth or of the alveolar process of the mandible or maxilla. In the present invention, resorption involves the loss of implant mass which has been introduced into the host body through normal physical (e.g., dissolution) or physiological processes. xe2x80x9cCellularly resorbablexe2x80x9d means a that a material is resorbable by a process involving a cellular process.
xe2x80x9cRemodelingxe2x80x9d is related to resorption and is the process of coordinately replacing or transforming the resorbed material into tissue without the formation of significant unwanted voids or detrimental intermediates. An exemplary remodeling is the coordinated resorption of a calcium phosphate bone cement and its replacement with new bone.

Malleable implant containing solid element that resorbs or fractures to provide access channels


A seat cushion for a vehicle seat unit comprising a cushioning pad upholstered with a seat covering and a flexible but inelastic planar film with an electrically conductive element buried therein that is disposed between the cushioning pad and the seat covering. The cushioning pad has tuck-in grooves in which the seat covering is locally retained. The planar film is thickened at locations where the planar film transverses the tuck-in grooves for reinforcement.

1. Field of the Invention
The present invention relates to a seat cushion for a vehicle seat unit that comprises a cushioning pad such as an urethane foam upholstered with a seat covering, and, more particularly, to a seat cushion for a vehicle seat unit in which a planer electrically conductive clement is disposed between a cushioning pad and a seat covering.
2. Description of Related Art
Typically, a seat cushion of a front seat unit or a rear seat unit for a vehicle comprises an elastic cushioning pad such as an urethane pad and a seat covering with which the elastic cushioning pad is upholstered. Some types of seat cushion are provided with a planar conductive clement such as comprised of a flexible but inelastic planar film with an electrically conductive element buried therein (that is hereafter referred to as a planar conductive film) that is disposed between the cushioning pad and the seat covering. In one example, the planar conductive film is used as a planar sensor device that detects an occupant sitting on the seat cushion or an occupant such as an infant or a small child secured in a child safety seat on the seat cushion.
Reference is made to FIGS. 10 through 15 showing prior art seat cushions with a planer conductive film embedded in a seat cushion between a cushioning pad and a seat covering for the purpose of providing a brief background that will enhance an understanding of the present invention.
Referring to FIG. 10 showing one of the prior art seat cushions for a vehicle seat unit, a seat cushion 80 comprises an elastic cushioning pad 81 preferably made of an urethane foam with its seating surface entirely upholstered with a seat covering (not shown). The seat cushion 80 is provided with a flexible but inelastic planar conductive film 82 embedded therein between the seat cushioning pad 81 and the seat covering. The elastic cushioning pad 81 has a plurality of U-shaped tuck-in grooves 83 (only one of which is shown) extending in both lengthwise and transverse directions. The seat covering is locally retained the tuck-in grooves 83 for preserving a designed appearance of the seat cushion 80, and strip sections of the planer conductive film 82 are laid in the tuck-in grooves 83 in a U- or V-shape. According to the seat cushion 80, when the seat cushion 80 repeatedly experiences an external impact load from above, while the cushioning pad 81 elastically contacts and recovers repeatedly, nevertheless, the planar conductive film 82 does not contract. In consequence, the nip sections of the planar conductive film 82 in the tuck-in grooves 83 are repeatedly loosened and stretched and led into breakage or damage as shown in FIG. 11. Such breakage or damage of the strip section of the planar conductive film 82 causes an electric disconnection of the electrically conductive element at the broken or damaged strip section laid in the tuck-in groove 83. The electric disconnection of the electrically conductive element is made more marked, if the tuck-in grooves 83 is made deeper for design requirements. Modified shapes of tuck-in groove 83 such as shown in FIGS. 12 through 15 are conceivably effective to eliminate an occurrence of breakage or damage of the strip section of the planar conductive film 82 in the tuck-in groove 83.
Referring to FIG. 12 showing a seat cushion 80 having one of the variations of tuck-in groove, a cushioning pad 81 has a tuck-in groove 83 locally provided with bridges 84 so that the tuck-in groove 83 is locally made shallow at locations where strip sections of a planar conductive film 82 traverse the tuck-in groove 83.
According to the seat cushion 80 having the cushioning pad 81 with the tuck-in grooves 83 locally made shallow, while the planar conductive film 82 is advantageously prevented from causing breakage or damage that is conductive to an electric disconnection of the electrically conductive element buried in the planer conductive film 82, nevertheless, the tuck-in groove 83 at the bridges 84 is made too shallow for the seat covering to provide a sufficient tuck-in depth for the seat covering. This tends toward an unattractive appearance of the seat cushion 80 and, in consequence, leads the seat unit into less marketability.
Referring to FIG. 13 showing a seat cushion 80 having another variation of tuck-in groove, a cushioning pad 81 has a tuck-in groove 83 locally provided a narrow inverted trapezoidal recesses 85 across the tuck-in grooves 83 at locations where strip sections of a planar conductive film 82 are laid in the tuck-in grooves 83. The inverted trapezoidal recess 85 comprises a flat bottom 85a at a level with the bottom of the tuck-in groove 83 and walls 85b slanting in opposite directions. After laying a strip section of the planer conductive film 82 in the inverted trapezoidal recess 85 in keeping with the walls 85a and 85b, triangular retaining pads 85c are forced into triangular spaces formed in the cushioning pad 81 by the inverted trapezoidal recess 85 at opposite sides of the tuck-in groove 83 so as thereby to prevent the strip section of the planer conductive film 82 from coming up. The triangular retaining pad 85 is preferably different in material from the cushioning pad 81.
According to the tuck-in groove 83 shown in FIG. 13, while the strip section of the planar conductive film 82 is prevented from coming up, and hence from being broken or damaged, by the triangular holding pads 85, nevertheless, the incorporation of the triangular retainer pads 85 leads to an increase in costs and manpower for manufacturing the seat cushion 80.
Referring to FIGS. 14 and 15 showing a seat cushion 80 having still another variation of tuck-in groove, a cushioning pad 81 has a tuck-in groove 83 and inverted trapezoidal grooves 86 across the tuck-in groove 83 at locations where strip sections of a planar conductive film 82 is laid in the tuck-in grooves 83. The inverted trapezoidal groove 86 at opposite sides has an open top end flanked with a pair of rounded retaining protrusions 87 at each of opposite sides of the tuck-in groove 83. Each rounded retaining protrusion 87 is formed as an integral portion of the cushioning pad 81. The strip section of the planar conductive film 82 is forced into the inverted trapezoidal groove 86 passing through the retaining protrusions 87 and laid in the tuck-in groove 83.
According to the tuck-in groove 83 shown in FIGS. 14 and 15, the strip section of the planar conductive film 82 is prevented from coming up and out of the tuck-in groove 83 by the retaining protrusions 87. While the tuck-in groove 83 thus constructed is advantageous in preventing the planar conductive film 82 from being damaged or broken, and hence an electric disconnection of the electrically conductive element, nevertheless, the tuck-in groove 83 inevitably reaches aggravation of setting easiness of the strip sections of the planar conductive film 82. That is, if the retaining protrusion 87 is made larger in order to prevent the strip section of the planar conductive film 82 from coming up and out of the tuck-in groove 83, it becomes an onerous task to tuck the strip section of the planar conductive film 82 in the tuck-in groove 83.
Another idea on eliminating an occurrence of breaking of an electrically conductive layer or film of a planar occupant sensor of a seat unit is disclosed in Japanese Unexamined Patent Publication No. 2000-318503. This planar occupant sensor has a protective sheet with an extension inserted between cushioning pad of a seatback and an adhesive layer so as to prevent the electrically conductive layer or film from breaking. However, the protection sheet is used only for protecting the electrically conductive layer or film. In addition, the electrically conductive layer or film is not laid in tuck-in grooves.