A method for establishing a connection between user equipment (UE) and an associated network includes receiving at the UE a service announcement providing a description of an available broadcast service and at least one identifier which identifies the broadcast service, and receiving at the UE a setup message which establishes a point-to-point radio bearer between the UE and the network, such that the setup message includes the identifier which is used to identify that the radio bearer carriers the broadcast service.

1. Field of the Invention
The present invention relates generally to wireless communication systems, and in particular to establishing a connection between user equipment and an associated network.
2. Discussion of the Related Art
A universal mobile telecommunication system (UMTS) is a European-type, third generation IMT-2000 mobile communication system that has evolved from a European standard known as global system for mobile communications (GSM). UMTS is intended to provide an improved mobile communication service based upon a GSM core network and wideband code division multiple access (W-CDMA) wireless connection technology.
In December 1998, a Third Generation Partnership Project (3GPP) was formed by the ETSI of Europe, the ARIB/TTC of Japan, the T1 of the United States, and the TTA of Korea. The 3GPP creates detailed specifications of UMTS technology. In order to achieve rapid and efficient technical development of the UMTS, five technical specification groups (TSG) have been created within the 3GPP for standardizing the UMTS by considering the independent nature of the network elements and their operations.
Each TSG develops, approves, and manages the standard specification within a related region. Among these groups, the radio access network (RAN) group (TSG-RAN) develops the standards for the functions, requirements, and interface of the UMTS terrestrial radio access network (UTRAN), which is a new radio access network for supporting W-CDMA access technology in the UMTS.
FIG. 1 gives an overview of the UMTS network, including the UE, the UTRAN and the core network. The UTRAN is composed of several radio network controllers (RNCs) and Node-Bs, which communicate via the Iub interface.
Each RNC controls several Node-Bs. Each RNC is connected via the Iu interface to the core network (CN), specifically to the MSC (mobile-services switching center) and the SGSN (serving GPRS support node) of the CN. RNCs can be connected to other RNCs via the Iur interface. The RNC handles the assignment and management of radio resources and operates as an access point with respect to the core network.
The Node-Bs receive information sent by the physical layer of the terminal through an uplink transmission and transmit data to the terminal through a downlink transmission. The Node-Bs operate as access points of the UTRAN for the terminal.
The SGSN is connected via the Gf interface to the EIR (equipment identity register), via the GS interface to the MSC, via the GN interface to the GGSN (gateway GPRS support node) and via the GR interface to the HSS (home subscriber server). The EIR maintains lists of mobiles that are allowed to be used on the network.
The MSC, which controls the connection for circuit switch (CS) services. The MSC is connected to the MGW (media gateway) via the NB interface, to the EIR via the F interface, and to the HSS via the D interface. The MGW is connected to the HSS via the C interface and to the PSTN (Public Switched Telephone Network). The MGW facilitates adapting the codecs between the PSTN and the connected RAN.
The GGSN is connected to the HSS via the GC interface, and to the Internet via the GI interface. The GGSN is responsible for routing, charging, and separation of data flows into different radio access bearers (RABs). The HSS handles the subscription data of the users.
The UTRAN constructs and maintains a radio access bearer (RAB) for communication between the terminal and the core network. The core network requests end-to-end quality of service (QoS) requirements from the RAB, and the RAB supports the QoS requirements set by the core network. Accordingly, the UTRAN can satisfy the end-to-end QoS requirements by constructing and maintaining the RAB.
The services provided to a specific terminal are roughly divided into circuit switched services and packet switched services. For example, a general voice conversation service is a circuit switched service, while a Web browsing service via an Internet connection is classified as a packet switched service.
For supporting circuit switched services, the RNCs are connected to the mobile switching center (MSC) of the core network, and the MSC is connected to the gateway mobile switching center (GMSC) which manages the connection with other networks. For supporting packet switched services, the RNCs are connected to the serving general packet radio service (GPRS) support node (SGSN), and the gateway GPRS support node (GGSN) of the core network. The SGSN supports the packet communications with the RNCs, and the GGSN manages the connection with other packet switched networks, such as the Internet.
FIG. 2 illustrates a structure of a radio interface protocol between the terminal and the UTRAN according to the 3GPP radio access network standards. As shown in FIG. 2, the radio interface protocol has vertical layers comprising a physical layer, a data link layer, and a network layer, and has horizontal planes comprising a user plane (U-plane) for transmitting user data and a control plane (C-plane) for transmitting control information.
The user plane is a region that handles traffic information with the user, such as voice or Internet protocol (IP) packets. The control plane is a region that handles control information for an interface with a network, maintenance and management of a call, and the like.
The protocol layers in FIG. 2 can be divided into a first layer (L1), a second layer (L2), and a third layer (L3) based on the three lower layers of an open system interconnection (OSI) standard model. The first layer (L1), or the physical layer, provides an information transfer service to an upper layer by using various radio transmission techniques. The physical layer is connected to an upper layer, called a medium access control (MAC) layer, via a transport channel.
The MAC layer and the physical layer exchange data via the transport channel. The second layer (L2) includes a MAC layer, a radio link control (RLC) layer, a broadcast/multicast control (BMC) layer, and a packet data convergence protocol (PDCP) layer.
The MAC layer handles mapping between logical channels and transport channels, and provides allocation of the MAC parameters for allocation and re-allocation of radio resources. The MAC layer is connected to an upper layer, called the radio link control (RLC) layer, via a logical channel.
Various logical channels are provided according to the type of information transmitted. In general, a control channel is used to transmit information of the control plane, and a traffic channel is used to transmit information of the user plane.
A logical channel may be a common channel or a dedicated channel depending on whether the logical channel is shared. Logical channels include a dedicated traffic channel (DTCH), a dedicated control channel (DCCH), a common traffic channel (CTCH), a common control channel (CCCH), a broadcast control channel (BCCH), and a paging control channel (PCCH) or a shared channel control channel.
The BCCH provides information including information utilized by a terminal to access a system. The PCCH is used by the UTRAN to access a terminal.
For the purposes of a multimedia broadcast/multicast service (MBMS) additional traffic and control channels are introduced in the MBMS standard. The MCCH (MBMS point-to-multipoint control channel) is used for transmission of MBMS control information. The MTCH (MBMS point-to-multipoint traffic channel) is used for transmitting MBMS service data. The MSCH (MBMS Scheduling Channel) is used to transmit scheduling information. The different logical channels that exist are listed in FIG. 3.
The MAC layer is connected to the physical layer by transport channels and can be divided into a MAC-b sub-layer, a MAC-d sub-layer, a MAC-c/sh sub-layer, a MAC-hs sub-layer and a MAC-m sublayer according to the type of transport channel being managed. The MAC-b sub-layer manages a BCH (broadcast channel), which is a transport channel handling the broadcasting of system information. The MAC-c/sh sub-layer manages a common transport channel, such as a forward access channel (FACH) or a downlink shared channel (DSCH), which is shared by a plurality of terminals, or in the uplink the radio access channel (RACH). The MAC-m sublayer may handle the MBMS data.
The possible mapping between the logical channels and the transport channels from a UE perspective is given in FIG. 4. The possible mapping between the logical channels and the transport channels from a UTRAN perspective is given in FIG. 5.
The MAC-d sub-layer manages a dedicated channel (DCH), which is a dedicated transport channel for a specific terminal. The MAC-d sublayer is located in a serving RNC (SRNC) that manages a corresponding terminal. One MAC-d sublayer also exists in each terminal.
The RLC layer, depending of the RLC mode of operation, supports reliable data transmissions and performs segmentation and concatenation on a plurality of RLC service data units (SDUs) delivered from an upper layer. When the RLC layer receives the RLC SDUs from the upper layer, the RLC layer adjusts the size of each RLC SDU in an appropriate manner based upon processing capacity and then creates data units by adding header information thereto. The data units, called protocol data units (PDUs), are transferred to the MAC layer via a logical channel. The RLC layer includes a RLC buffer for storing the RLC SDUs and/or the RLC PDUs.
The BMC layer schedules a cell broadcast (CB) message transferred from the core network and broadcasts the CB message to terminals positioned in a specific cell or cells.
The PDCP layer is located above the RLC layer. The PDCP layer is used to transmit network protocol data, such as the IPv4 or IPv6, effectively on a radio interface with a relatively small bandwidth. For this purpose, the PDCP layer reduces unnecessary control information used in a wired network, a function called header compression.
The radio resource control (RRC) layer located at the lowest portion of the third layer (L3) is only defined in the control plane. The RRC layer controls the transport channels and the physical channels in relation to setup, reconfiguration, and the release or cancellation of the radio bearers (RBs). Additionally the RRC handles user mobility within the RAN and additional services, such as location services.
The RB signifies a service provided by the second layer (L2) for data transmission between the terminal and the UTRAN. In general, the set up of the RB refers to the process of stipulating the characteristics of a protocol layer and a channel required for providing a specific data service, and setting the respective detailed parameters and operation methods.
The different possibilities that exist for the mapping between the radio bearers and the transport channels for a given UE are not all possible all the time. The UE and UTRAN deduce the possible mapping depending on the UE state and the procedure that the UE and UTRAN are executing. The different states and modes are explained in more detail below, as far as they concern the present invention.
The different transport channels are mapped onto different physical channels. For example, the RACH transport channel is mapped on a given PRACH, the DCH can be mapped on the DPCH, the FACH and the PCH can be mapped on the S-CCPCH, and the DSCH is mapped on the PDSCH. The configuration of the physical channels is given by RRC signaling exchange between the RNC and the UE.
The RRC mode refers to whether there exists a logical connection between the RRC of the terminal and the RRC of the UTRAN. If there is a connection, the terminal is said to be in RRC connected mode. If there is no connection, the terminal is said to be in idle mode.
Because an RRC connection exists for terminals in RRC connected mode, the UTRAN can determine the existence of a particular terminal within the unit of cells. For example, the UTRAN can determine in which cell or set of cells an RRC connected mode terminal is located and to which physical channel the UE is listening. Thus, the terminal can be effectively controlled.
In contrast, the UTRAN cannot determine the existence of a terminal in idle mode. The existence of idle mode terminals can only be determined by the core network to be within a region that is larger than a cell, for example, a location or a routing area. Therefore, the existence of idle mode terminals is determined within large regions, and in order to receive mobile communication services such as voice or data, the idle mode terminal must move or change into the RRC connected mode. The possible transitions between modes and states are shown in FIG. 6.
A UE in RRC connected mode can be in different states, such as CELL_FACH state, CELL_PCH state, CELL_DCH state, or URA_PCH state. Depending on the state, the UE carries out different actions and listens to different channels.
For example, a UE in CELL_DCH state will try to listen to DCH type of transport channels, among others. DCH types of transport channels include DTCH and DCCH transport channels, which can be mapped to a certain DPCH, DPDSCH or other physical channels.
The UE in CELL_FACH state will listen to several FACH transport channels, which are mapped to a certain S-CCPCH. A UE in PCH state will listen to the PICH channel and the PCH channel, which are mapped to a certain S-CCPCH physical channel.
The main system information is sent on the BCCH logical channel which is mapped on the P-CCPCH (primary common control physical channel). Specific system information blocks can be sent on the FACH channel. When the system information is sent on FACH, the UE receives the configuration of the FACH either on the BCCH that is received on P-CCPCH or on a dedicated channel. When system information is sent on the BCCH (i.e., via the P-CCPCH), then in each frame or set of two frames the SFN (system frame number) is sent which is used in order to share the same timing reference between the UE and the Node-B. The P-CCPCH is sent using the same scrambling code as the P-CPICH (primary common pilot channel), which is the primary scrambling code of the cell. The spreading code that is used by the P-CCPCH is of a fixed SF (spreading factor) 256, and the number is one. The UE knows about the primary scrambling code either by information sent from the network on system information of neighboring cells that the UE has read, by messages that the UE has received on the DCCH channel, or by searching for the P-CPICH, which is sent using the fixed SF 256, the spreading code number 0 and which transmits a fixed pattern.
The system information comprises information on neighboring cells, configuration of the RACH and FACH transport channels, and the configuration of MICH and MCCH which are channels that are dedicated channels for the MBMS service.
Each time the UE changes the cell it is camping (in idle mode) or when the UE has selected the cell (in CELL_FACH, CELL_PCH or URA_PCH) state, the UE verifies that it has valid system information. The system information is organized in SIBs (system information blocks), a MIB (master information block) and scheduling blocks. The MIB is sent very frequently and gives timing information of the scheduling blocks and the different SIBs. For SIBs that are linked to a value tag, the MIB also contains information on the last version of a part of the SIBs. SIBs that are not linked to a value tag are linked to an expiration timer. SIBs linked to an expiration timer become invalid and need to be reread if the time of the last reading of the SIB is larger than this timer value. SIBs linked to a value tag are only valid if they have the same value tag as the one broadcast in the MIB. Each block has an area scope of validity (cell, PLMN, equivalent PLMN) which signifies on which cells the SIB is valid. A SIB with area scope "cell" is valid only for the cell in which it has been read. A SIB with area scope "PLMN" is valid in the whole PLMN, a SIB with the area scope "equivalent PLMN" is valid in the whole PLMN and equivalent PLMN.
In general UEs read the system information when they are in idle mode, CELL_FACH state, CELL_PCH state or in URA_PCH state of the cells that they have selected or the cell that they are camping on. In the system information, they receive information on neighboring cells on the same frequency, different frequencies and different RAT (radio access technologies). This allows the UE to know which cells are candidates for cell reselection.
MBMS is introduced in the UMTS standard in the Release 6 of the specification (Rel-6). It describes techniques for optimized transmission of MBMS bearer service including point-to-multipoint transmission, selective combining and transmission mode selection between point-to-multipoint and point-to-point bearers. This is used in order to save radio resources when the same content is sent to multiple users, and enables TV-like services. MBMS data can be split into two categories, control plane information and user plane information. The control plane information contains information on the physical layer configuration, transport channel configuration, radio bearer configuration, ongoing services, counting information, scheduling information, and the like. In order to allow UEs to receive this information, MBMS bearer specific control information for the MBMS is sent to the UEs.
The user plane data of MBMS bearers can be mapped onto dedicated transport channels for a point-to-point service which is sent only to one UE, or on a shared transport channel for point to multipoint service which is transmitted to (and received by) several users at the same time.
Point-to-point transmission is used to transfer MBMS specific control/user plane information, as well as dedicated control/user plane information between the network and a UE in RRC connected mode. It is used for the multicast or the broadcast mode of MBMS. DTCH is used for a UE in CELL_FACH and Cell_DCH. This allows existing mappings to transport channels.
To allow cell resources to be used in an optimized manner, a function called counting has been introduced in MBMS applications. The counting procedure is used to determine how many UEs are interested in the reception of a given service. This is done by using the counting procedure shown in FIG. 7.
For example, a UE that is interested in a certain service receives information of the availability of a MBMS service. The network can inform the UE that it should indicate to the network its interest in the service in the same way such as by transmitting the "access information" on the MCCH channel. A probability factor included in the access information message determines that an interested UE will only respond with a given probability. In order to inform the network that the UE is interested in a given service, the UE will send to the network the RRC connection setup message or the cell update message in the cell that the UE has received the counting information. This message may potentially include an identifier indicating the service that the UE is interested in.
Point-to-multipoint transmission is used to transfer MBMS specific control/user plane information between the network and several UEs in RRC connected or idle mode. It is used for broadcast or multicast mode of MBMS.
In the case that the network operates on several frequencies, when a UE is camping on one frequency, and a MBMS service is transmitted on a different frequency, a UE may not be aware of the fact that a MBMS service is transmitted in the different frequency. Therefore the frequency convergence procedure allows the UE to receive information in frequency A that indicates in a frequency B that a given service is available.

Point to point radio bearers for a broadcasting service


The invention provides antibodies against Fibroblast Activation Protein (FAP) and methods of using the same.

Fibroblast Activation Protein (FAP) and Anti-FAP Antibodies
Human Fibroblast Activation Protein (FAP; GenBank Accession Number AAC51668), also known as Seprase, is a 170 kDa integral membrane serine peptidase (EC 3.4.21.B28). Together with dipeptidyl peptidase IV (also known as CD26; GenBank Accession Number P27487), a closely related cell-surface enzyme, and other peptidases, FAP belongs to the dipeptidyl peptidase IV family (Yu et al., FEBS J 277, 1126-1144 (2010)). It is a homodimer containing two N-glycosylated subunits with a large C-terminal extracellular domain, in which the enzyme's catalytic domain is located (Scanlan et al., Proc Natl Acad Sci USA 91, 5657-5661 (1994)). FAP, in its glycosylated form, has both post-prolyl dipeptidyl peptidase and gelatinase activities (Sun et al., Protein Expr Purif 24, 274-281 (2002)).
Human FAP was originally identified in cultured fibroblasts using the monoclonal antibody (mAb) F19 (described in WO 93/05804, ATCC Number HB 8269). Homologues of the protein were found in several species, including mice (Niedermeyer et al., Int J Cancer 71, 383-389 (1997), Niedermeyer et al., Eur J Biochem 254, 650-654 (1998); GenBank Accession Number AAH19190). FAP has a unique tissue distribution: its expression was found to be highly upregulated on reactive stromal fibroblasts of more than 90% of all primary and metastatic epithelial tumors, including lung, colorectal, bladder, ovarian and breast carcinomas, while it is generally absent from normal adult tissues (Rettig et al., Proc Natl Acad Sci USA 85, 3110-3114 (1988); Garin-Chesa et al., Proc Natl Acad Sci USA 87, 7235-7239 (1990)). Subsequent reports showed that FAP is not only expressed in stromal fibroblasts but also in some types of malignant cells of epithelial origin, and that FAP expression directly correlates with the malignant phenotype (Jin et al., Anticancer Res 23, 3195-3198 (2003)).
Due to its expression in many common cancers and its restricted expression in normal tissues, FAP has been considered a promising antigenic target for imaging, diagnosis and therapy of a variety of carcinomas. Thus, multiple monoclonal antibodies have been raised against FAP for research, diagnostic and therapeutic purposes.
Sibrotuzumab/BIBH1, a humanized version of the F19 antibody that specifically binds to human FAP (described in WO 99/57151), and further humanized or fully human antibodies against the FAP antigen with F19 epitope specificity (described in Mersmann et al., Int J Cancer 92, 240-248 (2001); Schmidt et al., Eur J Biochem 268, 1730-1738 (2001); WO 01/68708)) were developed. The OS4 antibody is another humanized (CDR-grafted) version of the F19 antibody (Wüest et al., J Biotech 92, 159-168 (2001), while scFv 33 and scFv 36 have a different binding specificity from F19 and are cross-reactive for the human and mouse FAP protein (Brocks et al., Mol Med 7, 461-469 (2001)). More recently, other murine anti-FAP antibodies, as well as chimeric and humanized versions thereof, were developed (WO 2007/077173, Ostermann et al., Clin Cancer Res 14, 4584-4592 (2008)).
Proteases in the tumor stroma, through proteolytic degradation of extracellular matrix (ECM) components, facilitate processes such as angiogenesis and/or tumor cell migration. Moreover, the tumor stroma plays an important role in nutrient and oxygen supply of tumors, as well as in tumor invasion and metastasis. These essential functions make it not only a diagnostic but also a potential therapeutic target.
Evidence for the feasibility of the concept of tumor stroma targeting in vivo using anti-FAP antibodies was obtained in a phase I clinical study with 131iodine-labeled F19 antibody, which demonstrated specific enrichment of the antibody in the tumors and detection of metastases (Welt et al., J Clin Oncol 12, 1193-1203 (1994). Similarly, a phase I study with sibrotuzumab demonstrated specific tumor accumulation of the 131I-labeled antibody (Scott et al., Clin Cancer Res 9, 1639-1647 (2003)). An early phase II trial of unconjugated sibrotuzumab in patients with metastatic colorectal cancer, however, was discontinued due to the lack of efficacy of the antibody in inhibiting tumor progression (Hofheinz et al., Onkologie 26, 44-48 (2003)). Also a more recently developed anti-FAP antibody failed to show anti-tumor effects in vivo in unconjugated form (WO 2007/077173).
Thus, there remains a need for enhanced therapeutic approaches, including antibodies with improved efficacy, targeting FAP for the treatment of cancers.
Antibody Glycosylation
The oligosaccharide component can significantly affect properties relevant to the efficacy of a therapeutic glycoprotein, including physical stability, resistance to protease attack, interactions with the immune system, pharmacokinetics, and specific biological activity. Such properties may depend not only on the presence or absence, but also on the specific structures, of oligosaccharides. Some generalizations between oligosaccharide structure and glycoprotein function can be made. For example, certain oligosaccharide structures mediate rapid clearance of the glycoprotein from the bloodstream through interactions with specific carbohydrate binding proteins, while others can be bound by antibodies and trigger undesired immune reactions (Jenkins et al., Nature Biotechnol 14, 975-81 (1996)).
IgG1 type antibodies, the most commonly used antibodies in cancer immunotherapy, are glycoproteins that have a conserved N-linked glycosylation site at Asn 297 in each CH2 domain. The two complex biantennary oligosaccharides attached to Asn 297 are buried between the CH2 domains, forming extensive contacts with the polypeptide backbone, and their presence is essential for the antibody to mediate effector functions such as antibody dependent cell-mediated cytotoxicity (ADCC) (Lifely et al., Glycobiology 5, 813-822 (1995); Jefferis et al., Immunol Rev 163, 59-76 (1998); Wright and Morrison, Trends Biotechnol 15, 26-32 (1997)). Protein engineering studies have shown that FcγRs interact with the lower hinge region of the IgG CH2 domain. Lund et al., J. Immunol. 157:4963-69 (1996). However, FcγR binding also requires the presence of the oligosaccharides in the CH2 region. Lund et al., J. Immunol. 157:4963-69 (1996); Wright and Morrison, Trends Biotech. 15:26-31 (1997), suggesting that either oligosaccharide and polypeptide both directly contribute to the interaction site or that the oligosaccharide is required to maintain an active CH2 polypeptide conformation. Modification of the oligosaccharide structure can therefore be explored as a means to increase the affinity of the interaction between IgG1 and FcγR, and to increase ADCC activity of IgG1s.
A way to obtain large increases in the potency of monoclonal antibodies, is to enhance their natural, cell-mediated effector functions by engineering their oligosaccharide component as described in Umaña et al., Nat Biotechnol 17, 176-180 (1999) and U.S. Pat. No. 6,602,684 (WO 99/54342), the contents of which are hereby incorporated by reference in their entirety. Umaña et al. showed that overexpression of β(1,4)-N-acetylglucosaminyltransferase III (GnTIII), a glycosyltransferase catalyzing the formation of bisected oligosaccharides, in Chinese hamster ovary (CHO) cells significantly increases the in vitro ADCC activity of antibodies produced in those cells. Overexpression of GnTIII in production cell lines leads to antibodies enriched in bisected oligosaccharides, which are generally also non-fucosylated and of the hybrid type. If in addition to GnTIII, mannosidase II (ManII) is overexpressed in production cell lines, antibodies enriched in bisected, non-fucosylated oligosaccharides of the complex type are obtained (Ferrara et al., Biotechn Bioeng 93, 851-861 (2006)). Both types of antibodies show strongly enhanced ADCC, as compared to antibodies with unmodified glycans, but only antibodies in which the majority of the N-glycans are of the complex type are able to induce significant complement-dependent cytotoxicity (Ferrara et al., Biotechn Bioeng 93, 851-861 (2006)). Alterations in the composition of the Asn 297 carbohydrate or its elimination also affect binding of the antibody Fc-domain to Fcγ-receptor (FcγR) and complement C1q protein, which is important for ADCC and CDC, respectively (Umaña et al., Nat Biotechnol 17, 176-180 (1999); Davies et al., Biotechnol Bioeng 74, 288-294 (2001); Mimura et al., J Biol Chem 276, 45539-45547 (2001); Radaev et al., J Biol Chem 276, 16478-16483 (2001); Shields et al., J Biol Chem 276, 6591-6604 (2001); Shields et al., J Biol Chem 277, 26733-26740 (2002); Simmons et al., J Immunol Methods 263, 133-147 (2002)).


A composite cable for distributing electrical power to components in an optical fiber network and for transmitting optical signals between optical fiber network components includes at least one layer of insulated electrical conductors arranged in side-by-side relation to provide a layer of conductors of a thickness substantially equal to the thickness of the conductors. The conductors of the at least one layer of conductors are S-Z stranded and surround the optical fibers which are loosely contained in at least one plastic buffer tube to provide desirable structural and operational features to the cable and to an optical fiber network in which the cable can be included.

Optical fiber is now used in a variety of telecommunication applications because of its small physical size and high bandwidth capacity.
An optical fiber access network provides for the distribution of telecommunications data among various locations, such as between a central office (CO) and a location remote from the CO, often called an optical network unit (ONU), over optical fibers.
In many current optical access networks, the active components in the CO, which include optical and electrical devices, are powered by the power that a power utility supplies directly to the building or facility housing the CO. The ONU likewise requires electrical power for converting optical signals to electrical signals for further processing and distribution and for converting electrical signals to optical signals for transmission back through the fiber network to the CO. This power can originate from the same source in the CO, or more often, originate from a power source located remotely from the CO. This remote power source (RPS) typically converts AC power supplied by the power utility to a lower voltage DC power suitable for handling by communications craftspersons.
The most common method of carrying the power from the CO or RPS to the ONU is via a standard copper twisted-pair telephone cable or a standard coaxial cable, neither of which contains optical fiber. In addition, it has been proposed to carry the power by using a composite cable including groups of twisted-pair telephone wires bundled together in some fashion with a plastic tube or tubes containing optical fibers. See U.S. Pat. No. 5,268,971, incorporated by reference herein.
These composite cables, however, are unsatisfactory in terms of their size, scalability, maneuverability and taut-sheath accessibility. Conventional composite cables which contain electrical conductors arranged as twisted pairs or bundles have a large diameter and are heavy in weight. These conventional cables are of such size and weight because two wires which are twisted as opposed to untwisted or wires which are grouped as opposed to layered require excess space. The space requirement of the electrical conductor portion of these composite cables typically constitutes the greatest proportion of the composite cable. The contribution of the electrical conductors to the size of the composite cable limits the scalability of the cable design in terms of the number of optical fibers and electrical conductors which can be included during cable manufacture, because the size of the cables utilized in optical fiber networks must satisfy preset standards as to duct sizes, splice enclosures entrance ports, installation equipment and termination hardware. Also, a composite cable which is heavy and has a large diameter is extremely bulky and, thus, hard to maneuver in storage and installation. In addition, conventional composite cables are not constructed to allow for ease of mid-span or taut-sheath access to the optical fibers without damage to the electrical conductors when the electrical conductors surround the optical fibers in the composite cable.
Furthermore, the need for twisting the telephone wires when they are used for power distribution is disappearing in modern fiber access networks because of an increased confidence in the reliability of the fiber network as the only communications medium and a decreased interest in having communication-grade twisted-pairs available for future use.
Therefore, there exists a need for a composite cable which is compact, has a small diameter, is lightweight, mechanically protects the optical fibers from damage, is scalable in terms of optical fiber and electrical conductor capacity, is easy to install and terminate, allows for ease of mid-span or taut-sheath fiber access without harm to either the fibers or the conductors and is compatible with modern optical access network limitations and standards.


A detection and hold circuit outputs a reference signal having a level proportional to an x-coordinate detection pulse input from an X-coordinate signal amplifier. A delay element delays the reference signal. An adder adds the x-coordinate detection pulse from the X-coordinate signal amplifier and a delayed signal from the delay element. Comparators obtain a coordinate detection pulse making a detection signal from another detection and hold circuit for an LCD voltage inversion pulse serve as a reference signal. Thus noise following the x-coordinate detection pulse is removed to generate a coordinate detection pulse with a reference value corresponding to the level of the LCD voltage inversion pulse to allow a stable coordinate detection to be achieved. A correction signal generation circuit reads out correction data stored in an internal memory and transmits the data as a correction signal to a correction voltage generation circuit in an x-coordinate detection period when the segment electrode placed in the lower position is scanned. The correction voltage generation circuit generates a correction voltage for canceling a voltage induced at the common electrode placed in the upper position based on the input correction signal and a bias power source input from a DC power supply circuit.

The present invention relates to a display-integrated type tablet device for use in a personal computer, a word processor, or the like.
As a means for inputting a handwritten letter or a figure into a computer or a word processor, there has been put into practical use a display-integrated type tablet device which is formed by laminating an electrostatic induction type tablet on a liquid crystal display and is capable of receiving an input of a letter or a figure into its electrostatic induction type tablet as if the letter or figure were written on paper by writing implements. However, in such a display-integrated type tablet device, electrodes are viewed as a grating on the display screen due to a difference in reflectance or transmittance between a portion having an electrode and a portion having no electrode, which has been a cause of degrading the quality of an image displayed on the liquid crystal display screen.
As a tablet free of the above-mentioned drawback, lately a display-integrated type tablet device as shown in FIG. 15 is proposed by the applicant of the present invention (Japanese Patent Application No. 3-46751 and a co-pending U.S. patent application Ser. No. 07/849,733) though it is not yet well known. It should be noted that the above-mentioned device is not a prior art, and herein described for better understanding of the present invention.
In the above-mentioned display-integrated type tablet device, electrodes concurrently serve as image display electrodes of a liquid crystal display (LCD) and as coordinate detection electrodes of an electrostatic type tablet device. There are provided in one frame period a coordinate detection period when designated coordinates on the tablet are detected and an image display period when an image is displayed as shown in FIG. 16 to time-sharingly effect the coordinate detection and image display.
Referring to FIG. 15, an LCD panel 101 is constructed by interposing liquid crystals between common electrodes Y.sub.1 through Y.sub.n (an arbitrary common electrode represented by Y hereinafter) and segment electrodes X.sub.1 through X.sub.m (an arbitrary segment electrode represented by X hereinafter) which are arranged at right angles to each other, in which each portion where a common electrode Y and a segment electrode X cross each other constitutes each pixel. In other words, n.times.m dot pixels are arranged in matrix in the LCD panel 101.
The above-mentioned display-integrated type tablet device has an advantage of permitting cost reduction as well as compact and light weight design by virtue of the concurrent use of the electrodes and drive circuits as those of the liquid crystal display and those of the electrostatic induction type tablet in addition to an advantage of making the grating-shaped electrodes invisible for a better image presentation in contrast to the conventional type formed by laminating the electrostatic induction type tablet on the liquid crystal display.
The above-mentioned display-integrated type tablet device operates as follows. A common electrode drive circuit 102 for driving the common electrode Y and a segment electrode drive circuit 103 for driving the segment electrode X are connected to a display control circuit 105 and a detection control circuit 106 via a switching circuit 104. The switching circuit 104 is controlled by a control circuit 107 so that it outputs an output signal from the display control circuit 105 to the common electrode drive circuit 102 and the segment electrode drive circuit 103 in an image display period or outputs an output from the detection control circuit 106 to the common electrode drive circuit 102 and the segment electrode drive circuit 103 in a coordinate detection period.
Although the switching circuit 104, the display control circuit 105, the detection control circuit 106, and the control circuit 107 are expressed dividedly in blocks in FIG. 15, the circuits are integrated in an LSI (Large Scale Integrated) circuit in practice. Therefore, the LSI cannot be strictly sectioned into such blocks in a practical circuit arrangement.
In the aforementioned image display period, a mode signal (mode) output from the control circuit 107 to the segment electrode drive circuit 103 and to the switching circuit 104 is switched to an image display mode. Consequently, the segment electrode drive circuit 103 selects the image display mode, while the switching circuit 104 switches so as to select and output an output signal from the display control circuit 105.
Then there are output, from the display control circuit 105, shift data s from a shift data output terminal S, an inversion signal fr from an inversion signal output terminal FR, a clock signal cp1 from a clock output terminal CP1, a clock signal cp2 from a clock output terminal CP2, and display data D.sub.0 through D.sub.3 from data output terminals D0 through D3.
The above-mentioned clock signal cp1 is a clock signal which has a period when pixels in one line display an image, and the signal is input as a clock signal cp1o to a clock input terminal YCK of the common electrode drive circuit 102 and a latch pulse input terminal XLP of the segment electrode drive circuit 103 via an output terminal CP1O of the switching circuit 104. The shift data s which is a pulse signal for selecting a specified common electrode Y is input as shift data (so) to a shift data input terminal DIO1 of the common electrode drive circuit 102 in synchronization with the clock signal cp1o via an output terminal SO of the switching circuit 104.
When the shift data so is input to the common electrode drive circuit 102, the pulse position of the shift data so is shifted in a shift register in synchronization with the clock signal cp1o, and drive pulses of a common electrode drive signal are applied to the common electrodes Y.sub.1 through Y.sub.n from output terminals O1 through On of the common electrode drive circuit 102 in correspondence with the shift position. The common electrode drive signal is generated based on bias power sources V.sub.0 through V.sub.5 supplied from a DC power supply circuit 112.
The above-mentioned clock signal cp2 is a clock signal which has a period being a division of a period when pixels in one line displays an image, and the signal is input as a clock signal cp2o to a clock input terminal XCK of the segment electrode drive circuit 103 via an output terminal CP2O of the switching circuit 104.
The image display data D.sub.0 through D.sub.3 are input as display data D.sub.0 o through D.sub.3 o to input terminals XD0 through XD3 of the segment electrode drive circuit 103 via output terminals D0O through D3O of the switching circuit 104, and then successively taken into a register in the segment electrode drive circuit 103 in synchronization with the clock signal cp2o. When all the image display data corresponding to the pixels in one line are taken in, the display data taken in are latched at a timing of the clock signal cp1o input to the latch pulse input terminal XLP. Then drive pulses of the segment electrode drive signal corresponding to the display data are applied from output terminals O1 through Om of the segment electrode drive circuit 103 to the segment electrodes X.sub.1 through X.sub.m. The segment drive signal is also generated based on the bias power sources V.sub.0 through V.sub.5 supplied from the DC power supply circuit 112.
It is noted that the inversion signal fr is a signal for preventing the possible deterioration of the liquid crystals due to electrolysis by periodically inverting the direction of voltage application to the liquid crystals in the image display period. The inversion signal fr is input as an inversion signal fro to an inversion signal input terminal YFR of the common electrode drive circuit 102 and an inversion signal input terminal XFR of the segment electrode drive circuit 103 via an inversion signal output terminal FRO of the switching circuit 104.
Thus the pixel matrix of the LCD panel 101 is line-sequentially driven by the operations of the above-mentioned common electrode drive circuit 102 and the segment electrode drive circuit 103 to display an image corresponding to the display data D.sub.0 through D.sub.3 on the LCD panel 101.
In the aforementioned coordinate detection period, the mode signal (mode) output from a control circuit 107 to the segment electrode drive circuit 103 and to the switching circuit 104 is switched to a coordinate detection mode. Consequently, the segment electrode drive circuit 103 selects the coordinate detection mode, while the switching circuit 104 switches so as to select and output an output signal from the detection control circuit 106.
Then there are output, from the detection control circuit 106, shift data sd from a shift data output terminal Sd, an inversion signal frd from an inversion signal output terminal FRd, a clock signal cp1d from a clock output terminal CP1d, a clock signal cp2d from a clock output terminal CP2d, and drive data D.sub.0 d through D.sub.3 d from data output terminals D0d through D3d.
The clock signal cp1d is a clock signal which has a period when one common electrode Y or one segment electrode X is scanned, and the signal is input as the clock signal cp1o to the clock input terminal YCK of the common electrode drive circuit 102 and the latch pulse input terminal XLP of the segment electrode drive circuit 103 via the output terminal CP1O of the switching circuit 104. Meanwhile, the shift data sd which is a pulse signal for selecting a specified common electrode Y or segment electrode X is input as the shift data (so) to the shift data input terminal DIO1 of the common electrode drive circuit 102 or to a data input terminal EIO1 of the segment electrode drive circuit 103 via the output terminal SO of the switching circuit 104 in synchronization with the aforementioned clock signal cp1d.
Then, in the same manner as described above, the pulse position of the shift data so input to the common electrode drive circuit 102 is shifted in a shift register in synchronization with the clock signal cp1o, and scanning pulses of common electrode drive signals y.sub.1 through Y.sub.n (arbitrary common electrode scanning signal represented by y hereinafter) are successively applied from the output terminals O1 through On corresponding to the shift position to the common electrodes Y.sub.1 through Y.sub.n. The common electrode scanning signal y is generated based on the bias power sources V.sub.0 through V.sub.5 supplied from the DC power supply circuit 112.
Meanwhile, the pulse position of the shift data so input to the segment electrode drive circuit 103 which has been selected to be in the coordinate detection mode is shifted in a shift register in synchronization with the clock signal cp1o, and scanning pulses of segment electrode drive signals x.sub.1 through x.sub.n (arbitrary segment electrode scanning signal represented by x hereinafter) are successively applied from the output terminals O1 through Om corresponding to the shift position to the segment electrodes X.sub.1 through X.sub.m.
Although the above described the case where the segment electrode X is scanned based on the shift data so and the clock signal cp1o, the segment electrode X may be scanned in the following manner. That is, the segment electrode scanning signal x is output to the segment electrodes X.sub.1 through X.sub.m from the output terminals O1 through Om of the segment electrode drive circuit 103 while making any bit of the drive data D.sub.0 d through D.sub.3 d output from the detection control circuit 106 serve as the shift data sd and making the clock signal cp2d serve as a sync signal.
In the above case, the clock signal cp2d is a clock signal which has a period when the segment electrode X is scanned, and the signal is input as the clock signal cp2o to the clock input terminal XCK of the segment electrode drive circuit 103 via the output terminal CP2O of the switching circuit 104.
The drive data D.sub.0 d through D.sub.3 d are input as drive data D.sub.0 o through D.sub.3 o to the input terminals XD0 through XD3 of the segment electrode drive circuit 103 via the output terminals D0O through D3O of the switching circuit 104, and then successively taken into the register of the segment electrode drive circuit 103 in synchronization with the clock signal cp2o. Then scanning pulses of the segment electrode scanning signals x.sub.1 through x.sub.m corresponding to the above-mentioned drive data are output from the output terminals O1 through O.sub.m of the segment electrode drive circuit 103 to segment electrodes X.sub.1 through Xm. The segment electrode scanning signal x is also generated based on the bias power sources V.sub.0 through V.sub.5 supplied from the DC power supply circuit 112.
It is noted that the output terminal EIO2 of the segment electrode drive circuit 103 is the output terminal of the final stage of the shift register, and the output terminal EIO2 outputs a pulse signal seio2 having the same pulse width as that of the shift data sd as shown in FIG. 18.
The segment electrode scanning signal x is also generated based on the bias power sources V.sub.0 through V.sub.5 supplied from the DC power supply circuit 112.
FIG. 20 is a timing chart of the scanning signals in the coordinate detection period of the above-mentioned display-integrated type tablet device. The coordinate detection period is separated into an x-coordinate detection period and a subsequent y-coordinate detection period. In the x-coordinate detection period, scanning pulses of the segment electrode scanning signal x are successively applied to the segment electrode X. In the y-coordinate detection period, scanning pulses of the common electrode scanning signal y are successively applied to the common electrode Y.
In the above case, the scanning pulse voltage of the segment electrode scanning signal x or the common electrode scanning signal y for one of the segment electrode X or the common electrode Y to be scanned (the voltage referred to as the "scanning voltage" hereinafter) is set at the bias power source V.sub.5 supplied from the DC power supply circuit 112. On the other hand, the scanning pulse voltage of the segment electrode scanning signal x or the common electrode scanning signal y for the other of the segment electrode X or the common electrode Y to be not scanned (the voltage referred to as the "non-scanning voltage" hereinafter) is set at the bias power source V.sub.1 supplied from the DC power supply circuit 112.
With application of the above-mentioned scanning signal V.sub.5, a voltage is induced at a designation coordinate detection pen (referred to merely as the "detection pen" hereinafter) 108 as shown in FIG. 17(b) due to a floating capacitance between the segment electrode X or the common electrode Y and a tip electrode of the detection pen 108 as shown in FIG. 17(a). The voltage induced at the detection pen 108 is amplified in an amplifier 109 and then converted into a binary signal as shown in FIG. 17(c) to be input to an x-coordinate detection circuit 110 and a y-coordinate detection circuit 111.
The x-coordinate detection circuit 110 and the y-coordinate detection circuit 111 detect the x-coordinate value or the y-coordinate value of a position designated by the detection pen 108 by detecting a period "T" from the time when the scanning voltage signal V.sub.5 is applied to the time when an induction voltage takes its maximum value based on an output from the amplifier 109 and a timing signal from the control circuit 107.
FIG. 21 shows a relation in position between the LCD panel 101 and the detection pen 108. When directly touching the LCD panel 101 with the detection pen 108, a stress is applied to a polarizer 114 and an LCD enclosure glass plate 115 to modulate the transmittance of the LCD panel 101, and consequently so-called a Newton-ring-shaped pattern appears. Therefore, a transparent protection plate 116 such as glass or acrylic resin is interposed between the LCD panel 101 and the detection pen 108 to provide an air gap 117 so as not to apply any stress onto the LCD panel 101.
However, in the display-integrated tablet construction as shown in FIG. 21, the stress onto the LCD panel 101 can be avoided but the transparent protection plate 116 is significantly deformed by the stress, which results in greatly varying the distance between the segment electrode X as well as the common electrode Y (referred to merely as the "scanning electrode" hereinafter) and a detection electrode 113 of the detection pen 108. In such a display-integrated type tablet device, coordinate detection is effected taking advantage of an electrostatic induction phenomenon. Therefore, the output of the detection pen 108 varies in reverse proportion to the distance between the scanning electrodes X and Y and the detection electrode 113.
Therefore, in a normal system where the analog output of the detection pen 108 is converted into a binary signal with a fixed threshold to obtain a detection pulse, there is a problem that a secured detection pulse cannot be obtained for a detection signal having a low signal-to-noise ratio.
In the above case, there can be presented an electrical equivalent circuit of the LCD panel 101 in the x-coordinate detection period when the common electrodes is fixed at the voltage V.sub.0 and the segment electrodes receive a voltage which changes from the voltage V.sub.0 to the voltage V.sub.5 and again to the voltage V.sub.0 as shown in FIG. 22. It is noted that rcd.sub.1 through rcd.sub.n are internal resistance values of the common electrode drive circuit 102, rsd.sub.1 through rsd.sub.m are internal resistance values of the segment electrode drive circuit 103, rc.sub.1'1 through rc.sub.n'm are resistance values of the common electrodes, rs.sub.1'l through rs.sub.n'm are resistance values of the segment electrodes, and each of C.sub.1'1 through C.sub.n'm is a capacitance of one pixel of the LCD.
In the above case, by ignoring the resistance values rs.sub.1'1 through rs.sub.n'm and assuming rc.sub.1'1 =rc.sub.1'2 = . . . =rc.sub.n'm =rc, rcd.sub.1 =rcd.sub.2 = . . . =rcd.sub.n =rcd, C.sub.1'1 =C.sub.1'2 = . . . =C.sub.n'm =C, and rsd.sub.1 =rsd.sub.2 = . . . =rsd.sub.m =rsd, the equivalent circuit as shown in FIG. 22 can be further simplified as shown in FIG. 23.
Referring to FIG. 23, each of the capacitors of segment electrodes to which is applied the voltage V.sub.0 has no electric charge, while each of the capacitors of the segment electrodes to which is applied the voltage V.sub.5 has an electric charge of (V.sub.5 -V.sub.0)/n/C. It is noted that the voltage V.sub.5 is simultaneously applied to four segment electrodes in FIG. 23.
When the scanning of the segment electrodes progresses by one clock pulse in the condition as shown in FIG. 23, a condition as shown in FIG. 24 is achieved. Consequently, there is formed a discharge current through the capacitor of the segment electrode X at which the electric potential has changed from the voltage V.sub.5 to the voltage V.sub.0. Meanwhile, there is formed a charge current through the capacitor of the segment electrode X at which the electric potential has changed from the voltage V.sub.0 to the voltage V.sub.5. Since rc/n can be ignored in comparison to rsd, the above-mentioned charge and discharge currents do not flow into the common driver.
However, as shown in FIG. 25, the charge and discharge currents of the capacitors flow into the common electrode drive circuit 102 at the time of starting the scanning of the segment electrode X (the voltage V.sub.5 is applied only to the segment electrode X.sub.1 closest to the common electrode drive circuit 102), and therefore a voltage drop takes place because of the output impedance of the common electrode drive circuit 102. Such a voltage drop is superimposed on the entire common electrodes.
A voltage drop due to the resistance of the common electrodes is additionally superimposed at the time of ending the scanning of the segment electrode X (the voltage V.sub.5 is applied only to the segment electrode X.sub.m farthest from the common electrode drive circuit 102) as shown in FIG. 26, and therefore an increased amount of noise takes place at the scanning end time as compared with the scanning start time.
In an arrangement of the LCD panel 101, the transparent protection plate 116, and the detection pen 108 as shown in FIG. 21, the electrostatic coupling between the detection electrode 113 of the detection pen 108 and the common electrodes is strong, and the electrostatic coupling between the detection electrode 113 and the segment electrodes is very weak. Therefore, the noise superimposed on the common electrodes exerts great influence. In the normal system where the analog output of the detection pen 108 is converted into a binary signal with a fixed threshold to obtain a coordinate pulse, the detection signal induced at the detection pen 108 in scanning the segment electrodes has a degraded signal-to-noise ratio as shown in FIG. 27.
The above fact also results in a problem that no secured coordinate pulse for detecting the x-coordinate value can be obtained.
In the above-mentioned electrostatic induction type tablet, the detection signal of the detection pen 108 is obtained as a signal of which DC component is lost. In the output of the detection pen in the display-integrated type tablet device employing an electrostatic induction type tablet, an LCD image display polarity inversion pulse, a y-coordinate detection pulse, and an x-coordinate detection pulse can be obtained as analog signals respectively in the image display period, the y-coordinate detection period, and the x-coordinate detection period. Therefore, a delay of a low-frequency component takes place due to a capacitive coupling in the x-coordinate detection circuit 110 and the y-coordinate detection circuit 111, and each of the pulses exerts a low-frequency interference with the other pulses, which results in the appearance of an error in coordinate detection.
FIG. 18 shows a timing chart of a segment electrode scanning signal x applied to the segment electrode X of the LCD panel 101 and waveforms of the output signal from the detection pen 108 or the amplifier 109 in the x-coordinate detection period. FIG. 19 shows an equivalent circuit of the common electrode drive circuit 102 and the segment electrode drive circuit 103 in the x-coordinate detection period.
Referring to FIG. 19, switch units S.sub.1, S.sub.2, . . . S.sub.m in the segment electrode drive circuit 103 successively apply the scanning voltage V.sub.5 to each segment electrode X, while switch units S.sub.1', S.sub.2', . . . S.sub.m' in the common electrode drive circuit 102 successively apply the scanning voltage V.sub.5 to each common electrode Y. The switch units are each composed of a CMOS (Complementary Metal Oxide Semiconductor) silicon gate circuit.
It is noted that resistors r.sub.c1, r.sub.c5, r.sub.s1, and r.sub.s5 are on-resistors.
The above-mentioned switch units S.sub.1, S.sub.2, . . . , S.sub.m-1, S.sub.m in the segment electrode drive circuit 103 are switched to the voltage V.sub.5 sequentially from S.sub.1 to S.sub.m. Thus the scanning voltage V.sub.5 of the segment electrode scanning signal x is applied to the segment electrode X sequentially from a segment electrode X.sub.1 located at an end of the LCD panel 101 to a segment electrode X.sub.m located at the other end as shown in FIG. 18. Referring to FIG. 19, the switch units S.sub.2, S.sub.3, and S.sub.4 are switched to the voltage V.sub.5 to apply the scanning voltage to the segment electrodes X.sub.2, X.sub.3, and X.sub.4, while the other switch units S.sub.1, S.sub.5, . . . S.sub.m are switched to the voltage V.sub.1 to apply the non-scanning voltage to the segment electrodes X.sub.1, X.sub.5, . . . X.sub.m.
When the segment electrode X is scanned in the above-mentioned manner, a voltage as shown by a waveform in FIG. 17(b) is induced at the detection electrode of the detection pen 108. The induction voltage is amplified in the amplifier 109 and then converted into a binary signal as shown by a waveform in FIG. 17(c). Then a peak time "T" of the induction voltage is obtained from the rise-time "T.sub.1 " and the fall-time "T.sub.2 " of the obtained binary signal to calculate the x-coordinate value designated by the tip end of the detection pen 108.
The induction voltage actually obtained through the segment electrode scanning has a waveform as shown by a waveform (d) in FIG. 18, where noise components F and R are detected at the scanning start time and at the scanning end time.
FIG. 18 shows a waveform (e) obtained by differentiating twice the induction voltage signal (referred to as the "detection signal" hereinafter) as shown by a waveform (d) in FIG. 18 in the amplification stage of the amplifier 109 to obtain a binary pulse as narrow as possible.
The voltage induced at the detection pen 108 when the detection pen 108 is placed on the LCD panel 101 ideally has a waveform as shown by a waveform (c) in FIG. 18. A detection signal having such an ideal waveform can be obtained when scanning the electrodes placed in the upper position closer to the detection pen 108 as in the case of the common electrode Y as shown in FIGS. 15, 17(a), and 19.
However, when scanning the electrodes placed in the lower position farther from the detection pen 108 as in the case of the segment electrode X, there is obtained a detection signal having the undesirable induction noise peaks (referred to as the "induction noise peak" hereinafter) F and R induced due to a voltage induced at the electrode (common electrode Y) placed closer to the detection pen 108 in addition to the peak S (referred to as the "detection peak" hereinafter) formed based on the electrode scanning signal as shown by a waveform (d) in FIG. 18.
Therefore, when scanning a portion near the segment electrode X.sub.1 or a portion near the segment electrode X.sub.m located at end portions of the LCD panel 101, the detection signal peak S appears at the time of starting or ending the scanning in the x-coordinate detection period. Therefore, the induction noise peak F or the induction noise peak R is superimposed on the detection signal peak S to result in a problem that the accuracy in detecting the x-coordinate by means of the tip end of the detection pen is degraded.
The induction noise peaks F and R as described above appear as follows.
Since the resistance of the on-resistors r.sub.c1 and r.sub.c5 (=about 1 k.OMEGA.) and the electrode resistance r of the common electrode Y as shown in FIG. 19 are great, when the segment electrode X in the lower position is scanned while switching the switch units S.sub.1, S.sub.2, . . . S.sub.m of the segment electrode drive circuit 103 successively to the voltage V.sub.5, e.g., when the segment electrodes X.sub.2, X.sub.3, and X.sub.4 are scanned, a current i caused by the scanning voltage applied to the segment electrodes X.sub.2, X.sub.3, and X.sub.4 flows through the segment electrodes X.sub.2, X.sub.3, and X.sub.4 by way of a floating capacitance C (about 10 pF/mm.sup.2) between the segment electrode X and the common electrode Y as shown by the arrow in FIG. 19 and then to the DC power supply circuit 112 by way of the on-resistor r.sub.s5 inside the segment electrode drive circuit 103.
Therefore, the voltage at the common electrode Y which should be the non-scanning voltage V.sub.1 shifts slightly to the scanning voltage V.sub.5 (to the lower voltage side) of the segment electrode X as shown by a waveform (a) in FIG. 18.
Therefore, when the detection pen 108 is put close to the LCD panel 101 in the condition as shown in FIG. 19, there is induced a voltage as shown by the waveform (d) in FIG. 18 containing the wavy induction noise peaks F and R as shown by the waveform (b) in FIG. 18 attributed to the voltage induced at the common electrode Y as shown by the waveform (a) in FIG. 18 in addition to the detection signal peak S at the detection electrode of the detection pen 108. As a result, the output signal from the amplifier 109 is to have a waveform (e) as shown in FIG. 18.
In contrast to the fact that the common electrode Y placed in the upper position directly faces the detection electrode of the detection pen 108, the segment electrode X placed in the lower position faces the detection electrode of the detection pen 108 by way of a gap attributed to the common electrodes Y. Therefore, the electrostatic coupling force between the common electrode Y and the detection electrode of the detection pen 108 is much greater than the electrostatic coupling force between the segment electrode X and the detection electrode. Therefore, despite that the voltage at the common electrode Y shifted toward the side of the lower voltage is extremely low as shown by the waveform (a) in FIG. 18, the voltage induced at the detection electrode based on the slight voltage variance has the same level as that of the detection signal peak S.
When the detection pen 108 is located in the center position of the LCD panel 101, the induction noise peaks F and R can be separable from the detection signal peak S as shown by the waveform (d) in FIG. 18, and therefore the induction noise peaks F and R exert less influence.
However, when the detection pen 108 is located near the segment electrode X.sub.1 or the segment electrode X.sub.m, the detection signal peak S and the induction noise peaks F and R are superimposed on each other, the detection signal peak S is to have a complicatedly distorted waveform. Therefore, even when the detection signal is converted into a binary signal, the correct x-coordinate of the tip of the detection pen 108 cannot be detected.
Particularly, the induction noise peak R has a polarity reverse to that of the detection signal peak S. Therefore, when the detection pen 108 is located near the segment electrode X.sub.m, the detection signal peak S and the induction noise peak R having opposite polarities are superimposed on each other to lower the level of the detection signal peak S to significantly reduce the coordinate detection accuracy. In an extreme case, the x-coordinate value cannot be detected.


One embodiment provides a method, involving: receiving, at a device, handwriting input from a user; detecting, using a processor, a location of at least a part of the handwriting input; and providing, on a display device, at least one adaptive line to guide the handwriting input; wherein the at least one adaptive line is positioned based on the location of at least a part of the handwriting input. Other aspects are described and claimed.

Since the development of the first electronic device, designers have been trying to create a method of interaction that feels natural and smooth. One of the most basic methods of human communication is handwriting. Thus tools were built to interpret human handwriting on a touch sensitive surface. The problem with these existing tools is ensuring the software can correctly interpret the handwriting input. It is known that electronic devices have a significant increase in the percent of correct matches when analyzing handwriting input that is written in a straight line. Even a tilt as small as 5 to 10 degrees may cause errors in the analysis and impact an electronic device's chance of correctly recognizing a user's handwriting input.
In order to have the user input their handwriting in the straightest way possible some methods make use of static lines, similar to ruled paper. However, due to the various types of input electronic devices can take and the various different languages users may input, no single spacing method is sufficient for every user.


A positioning device for a slide includes a mobile track, a fixed track, and an auxiliary slide panel. A transient restriction of the mobile track is created by means of a slide piece for restriction and a retainer. The mobile track is then pushed into the fixed track by force for the slide piece to automatically slide and retreat to depart from the restriction by the retainer for fast retraction of the mobile track.

(a) Field of the Invention
The present invention relates to a positioning device for a slide, and more particularly, to one provides a transient positioning for a mobile track in relation to a fixed track when the mobile track is extended and later the positioning is automatically released by applying a certain push force to the mobile track.
(b) Description of the Prior Art
When a mobile track is pulled out from a slide designed with better functionality that is generally available in the market, the mobile track is usually very difficult to be retracted into a fixed track of a slide due to the disposition of a positioning device at where the mobile track is incorporated with the fixed track so to prevent the mobile track from retraction, or the mobile track is retained in relation to the fixed track to prevent the former from being disengaged from the latter and a further release operation is provided to disengage the mobile track. Many improvements have been made and granted with or pending applications as taught in U.S. Pat. No. 6,367,899 (Taiwan Utility Model No. 190765), U.S. Pat. No. 6,412,891 (Taiwan Utility Model No. 191092), Taiwan Utility Model Nos. 215620, 216738, and 216739, and Taiwan Patent Application No. 092206231 (Publication No. 589968).
Whereas depending on the nature of the application of the slide, the mechanical demands on the slide varies. Therefore, the development of an even more appropriate product is necessary. The present invention differs from those patents cited above in that the positioning function to prevent the mobile track from being retracted is designed with a feature of "mandatory release" to facilitate the retraction of the mobile track.


A process for cutting or splitting at least one optical fiber at a predetermined angle, wherein the fiber is introduced into a holding and positioning device and is cut by a pulsed laser beam.

Optical fibers made of glass are often used in optical transmission systems and other optical systems. The machining of the end face of these fibers plays a crucial role during the use of these monomode or multimode fibers. It is important that the end faces have a particularly uniform surface so that the transition from one fiber end to another or to an active element can be carried out with damping values which are as low as possible. It is also important that the end faces of the fibers can be produced at predetermined angles and that these angles are reliable and reproducible.
Various mechanical processes are currently known for severing optical fibers. With these processes, the fiber is typically fixed in a holding device consisting of two holders which are then mutually offset, for example, so that the correct angle is ensured during the cutting operation (see, e.g., EP 351,225.) To effect the cut, a tradition cleaving mechanism such as a diamond cutter is used. It is also known to twist the fiber or begin to cut and then break the fibers along the partial cut. After the fiber is cut, its end face is then polished to minimize optical losses.
The mechanical approach of cleaving and polishing a fiber has a number of significant shortcomings. For example, the multiple steps required makes this approach time-consuming, and, thus, expensive. The approach of mechanically cleaving and polishing a fiber also tends to be limited in flexibility. For example, ribbon cable can be cut only under limited conditions. Furthermore, the angle of the end face of a fiber is generally limited to less than 15° due to the excessive forces the polishing pad imparts to the fiber as the angle increases. As used herein, the phrases "angle of the end face" and "end face angle" refer to the angle from a perpendicular of the optical axis of the fiber. As the end face angle increases, the axial force component of the pad on the fiber increases. Glass fiber tends to lack axial strength. At some point, the axial force component, in combination with the torsional force component, causes the fiber tip to fracture. Although this point various depending upon the polishing technique, the end face angle is generally below 15°.
Therefore, there is a need for preparing the end face of a glass fiber which is inexpensive, versatile, and not limited to certain end face geometries. The present invention fulfills this need among others.


Core samples may been collected in a subterranean formation, preserved downhole in a pressurized nuclear magnetic resonance (NMR) core holder (1) comprising components for NMR imaging and (2) capable of maintaining the core samples at downhole fluid saturation state. For example, a pressurized NMR core holder may comprise a housing capable of containing downhole fluid pressures; a coil holder lining an inside of the housing and defining a core chamber; and one or more NMR coils maintained in a longitudinal position along the housing by the coil holder. Further, a system for performing the NMR imaging may comprise: a holder that maintains a pressurized NMR core holder in a desired position; and one or more magnets that are longitudinally movable along the pressurized NMR core holder.

The present application relates to nuclear magnetic resonance (NMR) of core samples.
Often samples of subterranean formations referred to as core samples are acquired via core drilling methods. The core samples are then analyzed to determine the properties (e.g., porosity, oil content, water content, and the like) of the portion of the formation from which they were acquired.
In order to analyze core samples from a subterranean formation, a core apparatus drills a core sample. Once at the surface, the core sample is often preserved by hermetically sealing the core sample in a thick coating of wax or by freezing with dry ice. The purpose of preservation is primarily to maintain the core and any fluids therein and the distribution of those fluids in the core sample as close as possible to reservoir conditions. However, as the native pressure of the core sample is invariably much higher than the pressure at the surface, the gases and light fluids that may have been trapped in the rock will escape from the core sample as it is brought to the surface thus making the core sample less accurate in providing a picture of the subterranean formation from which the core sample was taken.


A paper sheet processor includes a paper sheet setting portion for setting a plurality of paper sheets approximately uniformed in face-and-back orientation, a feeding section for sequentially introducing the paper sheets set on the paper sheet setting portion one after another, a discriminator for discriminating at least face-and-back orientation of each paper sheet introduced, a first stacker as a main stacker, a second stacker as a sub-stacker having a smaller capacity than that of the first stacker, and a controller for controlling such that the paper sheet first fed and discriminated in face-and-back orientation by the discriminator and any paper sheets subsequently fed and discriminated to have the same face-and-back orientation as that of the first fed paper sheet are stacked in the first stacker, and the other paper sheets discriminated to be different in face-and-back orientation from the first fed paper sheet are stacked in the second stacker. Even when a bundle of paper sheets to be re-checked, which are approximately uniform in face-and-back orientation, are set in the paper sheet processor in erroneous-face-and-back orientation, the processor can rationally carry out face-and-back re-orientation by stacking the front-faced or back-faced majority part of the paper sheets in the main stacker having a larger capacity and stacking the back-faced or front-faced minority of the paper sheets in the sub-stacker having a smaller capacity.

1. Field of the Invention
This invention relates to a paper sheet processor, and more particularly to a banknote processor having a plurality of stackers and capable of efficiently re-checking banknotes.
2. Description of the Background Art
U. S. Patent Publication No. 4,830,742 discloses a prior art concerning a banknote processor having a plurality of stackers and the function of discriminating face-and-back orientations of banknotes.
This prior-art banknote processor has three stackers, namely two sorting stackers and one rejection stacker. Based on judgment about face-and-back orientation by a discriminator, the processors stacks front-faced banknotes on the upper sorting stacker, and back-faced banknotes on the lower sorting stacker, so as to uniform the face-and-back orientation of banknotes.
Since the processor shown in the publication uses two sorting stackers equal in volume, it can efficiently uniform the face-and-back orientation of bank notes when it deals with a random mixture of front-faced banknotes and back-faced banknotes. However, when it is used for re-checking banknotes previously uniformed in face-and-back orientation to a certain extent, much more banknotes are stacked in one of the sorting stackers, and it is not rational from the viewpoint of stacking space.
For the purpose of use the processor shown in the publication in re-checking banknotes, it could be modified by omitting one of the sorting stackers so as to stack back-faced banknotes in the rejection stacker.
In this case, however, if an operator using the banknote processor erroneously puts approximately uniformly faced banknotes on a setting portion, facing majority""s back faces upward, then the back-faced majority banknotes set on the machine are stacked in the rejection stacker with a smaller containing space, and the rejection stacker soon become full.
This kind of problem generally occurs not only with banknotes but also with any kinds of paper sheets such as securities.
It is therefore an object of the invention to provide a paper sheet processor capable of uniforming face-and-back orientation of paper sheets regardless of the way of setting the paper sheets, and suitable for re-checking paper sheets approximately uniformed in face-and-back orientation previously.
According to the invention, there is provided a paper sheet processor comprising: a paper sheet setting portion for setting a plurality of paper sheets approximately uniformed in face-and-back orientation; a feeding section to sequentially feed the paper sheets set on said paper sheet setting portion one after another; a discriminator for discriminating at least face-and-back orientation of each paper sheet introduced; a first stacker as a main stacker; a second stacker as a sub-stacker having a smaller capacity than that of the first stacker; and a controller for controlling such that the paper sheet first introduced and discriminated in face-and-back orientation by the discriminator is stacked on the first stacker, and regarding second and subsequent paper sheets, those having the same face-and-back orientation as that of the first introduced paper sheet are stacked on the first stacker and the others having the opposite face-and-back orientation from that of the first introduced paper sheet are stacked on the second stacker.
Also when the second paper sheet, et seq. do not coincide with the first paper sheet in orientation of a pattern, denomination of banknotes or genuineness, the discriminator can stack paper sheets in a second stacker.
According to the invention, even when an operator erroneously puts approximately uniformly faced paper sheets on a setting portion, facing majority""s back faces upward, the processor sorts the majority front-faced or back-faced paper sheets to the main stacker having a larger capacity and the minority back-faced or front-faced paper sheets to the sub-stacker having a smaller capacity, thereby to rationally uniform the face-and-back orientation.

Paper sheet processor and method of processing paper sheet


A method is provided for fabricating a thin-film transistor (TFT). The method includes forming a semiconductor layer over a gate insulator that covers a gate electrode, and depositing an insulator layer over the semiconductor layer, as well as etching the insulator layer to form a patterned etch-stop without losing the gate insulator. The method also includes forming a source electrode and a drain electrode over the semiconductor layer and the patterned etch-stop. The method further includes removing a portion of the semiconductor layer beyond the source electrode and the drain electrode such that a remaining portion of the semiconductor layer covers the gate insulator in a first overlapping area of the source electrode and the gate electrode and a second overlapping area of the drain electrode and gate electrode.

Liquid crystal displays (LCDs) generally display images by transmitting or blocking light through the action of liquid crystals. LCDs have been used in a variety of computing displays and devices, including notebook computers, desktop computers, tablet computing devices, mobile phones (including smart phones) automobile in-cabin displays, on appliances, as televisions, and so on. LCDs often use an active matrix to drive liquid crystals in a pixel region. In some LCDs, a thin-film transistor (TFT) is used as a switching element in the active matrix.
FIG. 1A illustrates a perspective view of a sample electronic device, such as a tablet computer. The electronic device includes a touch screen display 100 enclosed by a housing 138. The touch screen display 100A incorporates a cover glass 102 and an LCD 100B behind the cover glass 102, although alternative embodiments may employ an organic light-emitting display (OLED) layer instead of an LCD. The LCD 100B is not shown in FIG. 1A.

Gate insulator loss free etch-stop oxide thin film transistor


Devices with gamma (γ) grooves are disclosed. The γ grooves can be used to form optical fiber arrays. The γ grooves can be formed using a dry etch, such as RIE, by modifying resist features of an etch mask to have convex curved sidewalls. The profile of the resist features is transferred to the substrate by the dry etch to form the γ grooves. The γ grooves are formed without K containing etchants, avoiding K+ ions contamination of process tools as well as health issues caused by handling alkali containing devices.

Fiber arrays are used for various types of applications, such as silicon photonic (SiPh) systems, including optical switching for communications as well as sensing applications where spatial optical data is employed, such as DNA sequencing, astronomy and nuclear research. The ends of optical fibers of the fiber array are maintained in fixed positions using a fiber array block with grooves or channels. The optical fibers are aligned in relations to other components of the optical system, such as other optical fibers, a planar waveguide or an opto-electronic device.
Conventional fiber array blocks employ v-grooves to fix the positions of the optical fibers. The v-grooves are formed by wet chemical etching technology which requires the usage of alkaline solutions containing KOH. However, such KOH solutions often cause contamination issues. In particular, K+ ion is an extremely fast-diffusion alkali metal ion which is detrimental to metal oxide semiconductor (MOS) devices. Furthermore, handling fiber arrays contaminated with K+ ions can cause health issues, making them a safety hazard.
U-groove fiber array blocks have been investigated. U-grooves are formed by an excimer laser ablation technology. However, laser ablation is not capable of precisely controlling small core pitches due to large laser beam size, which typically is about a few square centimeters. This may result in optical fibers being loosely fitted into the u-grooves, adversely affecting coupling efficiency. In addition, laser ablation is not feasible for manufacturing commercial fiber arrays because of long processing time due to small beam size.
The present disclosure is directed to fiber array blocks and fiber arrays.

Gamma groove arrays for interconnecting and mounting devices


An aspect of the present invention is directed to a display device including: an array substrate arranged with a plurality of pixels each having a light-emitting element are arranged; a first resin layer covering the plurality of pixels and having a first surface subjected to an alignment process; polarizers disposed over the first surface and aligned according to the alignment process; and a counter substrate disposed over the first resin layer.

An organic electroluminescence (hereinafter referred to as "organic EL") display device has light-emitting elements corresponding to each separate pixel and displays an image by individually controlling the emission of light. Each of the light-emitting elements includes an anode, a cathode, and a layer containing an organic EL material (hereinafter also referred to as "light-emitting layer"). The light-emitting layer is sandwiched between the anode and the cathode. The injection of electrons into the light-emitting layer through the cathode and the injection of holes into the light-emitting layer through the anode cause the electrons and the holes to recombine with each other. This discharges excess energy that excites luminescent molecules contained in the light-emitting layer, and then the luminescent molecules are deexcited to emit light.
In the organic EL display device, the anode of each of the light-emitting elements is provided as a pixel electrode for each pixel, and the cathodes are provided, for example, across the plurality of pixels as a common electrode to which a common potential is applied. The organic EL display device controls the emission of light from the pixels by applying the potential of the pixel electrode for each pixel with respect to the potential of the common electrode. It should be noted that the configuration in which the cathodes are disposed across the plurality of pixels and a common potential is applied to each of the pixels may be replaced by a configuration in which common potentials are individually applied to each separate pixel.
Note here that, for high efficiency in the extraction of light, it is preferable that the pixel electrodes be made of a metal material having a high reflectivity. However, if outside light enters the organic EL display device and becomes visible by being reflected by the pixel electrodes, the viewability of a display image will be degraded. In order to prevent such outside light reflections, it is necessary to provide the organic EL display device with a circularly polarizing plate.
In general, a polarizing plate is formed by drawing polyvinyl alcohol (PVA) (for example, Japanese Unexamined Patent Application Publication No. 2015-210459).
However, such formation of a polarizing plate by drawing polyvinyl alcohol (PVA) is difficult and poses problems in terms of manufacturing cost.
Further, bendable flexible display devices have recently been under vigorous development. However, depending on its thickness and hardness, a polarizing plate suffers from stress concentration when the display device is bent, with the result that the bent part may get cloudy or cracked.

Display device and method of manufacturing the same


Disclosed is a method for preparing a platinum/support catalyst or a platinum alloy/support catalyst, including: a) preparing a dispersion solution including urea, a support and a water-soluble salt of at least one metal(s) having catalytic activity; (b) reacting the dispersion solution at high temperature so as to deposit the metal hydroxide particles derived from the at least one metal(s) on the support; and (c) reducing the metal hydroxide particles. The size and distribution of the platinum particles or platinum alloy particles are greatly improved by the use of urea.

Carbon and metal oxides on which metal nanoparticles are loaded have been studied as catalysts and adsorbents for various organic and electrochemical reactions, including epoxy reaction, Heck reaction, oxidation and reduction in a fuel cell or a lithium-ion battery, hydrogen storage, or the like. Especially, a fuel cell which converts chemical energy to electrical energy via an electrochemical reaction by supplying fuel such as hydrogen or methanol is a next-generation, environment-friendly energy source, requiring no exchange or recharging of the cell as long as fuel continues to be provided to the cell. The fuel cell has been gaining attentions as an alternative energy source for environment-friendly automobiles, home and portable electronics and is being studied actively. The electrode performance of a fuel cell is greatly affected by the chemical composition, size, distribution, stability, etc. of catalyst nanoparticles for the oxidation and reduction electrodes. Further, it is also significantly affected by the easiness of mass transfer such as diffusion of reactants to the catalytic layer or discharge of reaction products, which in turn is related with the reaction surface area, pore structure, distribution and connectivity in the electrode catalytic layer.
Especially, proton exchange membrane (PEM) or polymer electrolyte membrane (PEM) fuel cells are of great interest as an energy source for applications requiring large power such as vehicles and transportations. The principle of the PEM fuel cell is as follows. The fuel cell includes an anode, a cathode and a polymer electrolyte membrane which physically separates them. At the anode, hydrogen or alcohol such as ethanol, methanol, etc. is supplied, and oxygen is supplied to the cathode. If a circuitry is constructed after connecting wires to the anode and the cathode by, for example, connecting an external power consuming circuit, the fuel cell begins operation. Recently, technical developments of a hydron-fed PEM fuel cell or direct-methanol fuel cell (DMFC), a type of a PEM fuel cell, have been made actively and commercialization is not distant. However, the commercialization of such fuel cells is hindered by some challenges, one of them being the high cost of platinum (Pt)-based catalysts. To solve this problem, efforts have been made to improve catalytic activity and thereby reduce the usage of platinum.
In general, it is known that the activity of a catalyst loaded on a support is largely dependent on the size and dispersity of metal particles. In order to reduce the size of platinum or platinum-M (M=Ru, Rh, Mo, Os, Ir, Re, Pd, V, W, Co, Fe, Se, Ni, bi, Sn, Cr, Cu, Ti, Au, Ce, . . . , Fe—Mo, Fe—Co, Ru—Fe, Ru—Co, Ru—Mo, . . . , Ru—Fe—Co, Ru—Fe—Mo, . . . etc) alloy particles and improve dispersity, various catalyst synthesis strategies have been developed, including impregnation reduction, colloidal methods, microemulsion methods, ion exchange, or the like. However, most of them are unsuccessful in adequately controlling particle size and dispersion, or are very complex, time-consuming and ineffective in removing residual protective agents.
Although these methods allow a relatively small and narrow size distribution of catalyst nanoparticles at low loading conditions of 20 to 30 wt %, the size, distribution and dispersion become unsatisfactory at high loading of 40 wt % or more. Further, since the synthesis is mainly carried out at high temperature, and expensive solvents and sometimes environmentally harmful chemicals are used, the methods are disadvantageous in cost and may result in environmental pollution. Also, the complex processes involved are time-consuming and, especially under metal loading, it is difficult to control the particle size, distribution and dispersion. Accordingly, there is an increasing need on the development of a stable, easy and effective catalyst synthesis method allowing the preparation of platinum or Pt-M alloy nanoparticles that can be dispersed uniformly and loaded stoichiometrically uniformly.

Process of preparing PT/support or PT alloy/support catalyst, thus-prepared catalyst and fuel cell comprising the same

Korea University Research and Business Foundation


The specification relates to retro-reflectors of the type used for road signs and markers and vehicle license plates to make these objects more noticeable to road users after dark. In the invention, the surface of a metal substrate is made retro-reflective by applying a layer of an organic polymeric material and adhering glass beads thereto, and then passing the substrate through a roller mill or the like with the glass beads covered by a platen so that the beads form indentations in the metal surface. The presence of the platen allows the pressing (indentation) step to take place without damage to the glass beads or to the layer between the beads and the metal surface. By this means, a hard metal article can be made directly retro-reflective.

This invention relates to retro-reflective sheet material (also known as reflex reflectors) and to a method of preparing the same.
Retro-reflective material is well known and widely used in the prior art, mainly in connection with road signs and automobile licence plates and the like. The material is capable of reflecting an incident beam of light back in the general direction of the light source. When, for example, a car headlight illuminates a road sign bearing such material in otherwise dark surroundings, the sign reflects a greater amount of light towards the driver than surrounding objects and is therefore clearly visible.
Known retro-reflective materials fall into two general types. The first type consists of spherical glass beads adhered to the surface of a transparent organic coating applied over a reflective metal (or other) substrate but only partially imbedded in it so that a glass-air interface is presented to incoming light. This type of material does not function as a retro-reflector when the surface is wet with water.
The second type of material consists of high refractive index (about 1.9 and greater) glass beads suspended within a relatively thick film of a transparent organic coating (plastic film) applied over a reflective metal substrate. Such material retains its retro-reflective properties when wet.
Theoretical considerations dictate that the most effective retro-reflectors of the second type can be formed by positioning the glass beads at just the right distance from conforming segments of concave spherical mirrors of corresponding size located behind the individual beads. This optimum distance will vary depending on the diameter of the beads, their refractive index, and the refractive index of the medium in which they are suspended.
Various known retro-reflectors embody such a structure but have generally been produced in the form of flexible tapes or sheets which are adhered to the desired object, such as a road sign. The step of adhering the tape to the object can be time consuming and uneconomical, and the tape may peel from the object after a period of exposure to the elements.
One example of known retro-reflectors is disclosed in U.S. Pat. No. 2,407,680 issued on Sept. 17, 1946 and assigned to Minnesota Mining and Manufacturing Company. This patent was one of the first to disclose the second type of structure referred to above employing high refractive index spheres, and it is to be noted that it suggests the use of a polished metal surface as the back reflector with the beads spaced an optimum distance therefrom. The patent also suggests the formation of concave mirrors in a reflective surface formed by a reflective binder layer for the heads.
U.S. Pat. No. 2,543,800 issued on Mar. 6, 1951 and assigned to Minnesota Mining and Manufacturing Company discloses a retro-reflector in which the beads are spaced a small distance from corresponding reflector surfaces formed by pressing the beads partially into a moldable cushion layer having a reflective surface coating containing metallic flake pigment particles, the beads being spaced from the cushion layer by a thin film which may contain a transparent pigment. After the pressing operation the plastic layers are cured. One disadvantage of such retro-reflectors is that the reflector surfaces formed by the cushion layer are not as reflective as a polished metal surface and therefore light is lost at these surfaces.
U.S. Pat. No. 3,922,433 issued on Nov. 25, 1975 and assigned to Aluminum Company of America relates to partially embedding the spherical glass beads into a metallic coating while it is in the molten condition. This invention is an attempt to form a retro-reflective surface directly on a substrate made of a hard material, such as a road sign, without first forming a flexible tape to be adhered thereto. An iron-base substrate is dipped into a molten bath of aluminum, zinc, tin, lead or alloys thereof and is sprayed with the glass beads by an air gun as the substrate is withdrawn from the bath and the coating is still molten. This method has the disadvantages that it is expensive and the beads are not spaced from the reflective surface as is required for the optimum retro-reflection.
There is therefore a need for a method of producing a retro-reflective surface directly onto hard metal substrates, which method permits the beads to be spaced by the optimum distance from conforming concave reflective surfaces.
The formation of a plastic layer containing the glass beads and the pressing of the beads into the metal substrate has been contemplated but, because of the relative hardness of the substrate surface, it has been found that the beads tend to shatter and the layer of plastic between the beads and the substrate surface tends to become attenuated or damaged when the plastic layer is rolled with sufficient force to cause the beads to indent the substrate surface. Moreover, the beads tend to become mis-aligned with the indentations in the surface so that a useless product is produced.

Retro-reflecting sheet material and method of making same