A semiconductor memory device that enables data buses to operate at high speed by reducing wiring capacitance and interference noise between data bus lines is provided. A semiconductor memory device includes a read-only data bus which is formed in a first metal layer and has plural pairs of read lines precharged to an arbitrary voltage and two lines in a pair transmitting complementary read signals. A write-only data bus, which is positioned in parallel with the read-only data bus, is formed in a second metal layer different from the first metal layer and has plural pairs of write lines precharged to an arbitrary voltage, and two lines in a pair transmitting complementary write signals.

The present invention relates to a semiconductor memory device for storing desired data therein and performing reading or writing of data therefrom and thereto at high speed.
Among various kinds of semiconductor memory devices, dynamic random access memory (hereinafter referred to as DRAM) has been often used as a mass storage device.
Referring to FIGS. 1, 12 and 13, a DRAM of Conventional Example 1 will be explained.
FIG. 1 shows the structure of the DRAM of Conventional Example 1 in schematic form. (FIG. 1 also applies to Embodiments.)
The DRAM will be described below with reference to FIG. 1.
The DRAM as shown in FIG. 1 has a memory subarray 1, a sense amplifier subarray 2, a peripheral circuit area 3, a write-only data bus 4 and a read-only data bus 5.
In the memory subarray 1, a plurality of DRAM cells is arranged in an array. In the sense amplifier subarray 2, a plurality of sense amplifier for detecting and amplifying a small signal of the memory subarray 1 is arranged in an array. The peripheral circuit area 3 receives or sends data from/to outside. The write-only data bus 4 transfers data from the peripheral circuit area 3 to a memory cell via the sense amplifier. The read-only data bus 5 transfers data in a memory cell amplified by the sense amplifier to the peripheral circuit area 3.
Operations of the conventional DRAM thus constructed will be described below.
In writing data from outside into a memory cell, the data from the peripheral circuit area 3 is written into the sense amplifier subarray 2 through the write-only data bus 4 and then the data in the sense amplifier subarray 2 is written into a designated memory cell through a bit line.
In reading data to outside, data in a memory cell is amplified by the sense amplifier subarray 2 via a bit line and then the amplified data is transferred to the peripheral circuit area 3 through the read-only data bus 5 to read out.
FIG. 12 is a schematic view illustrating data buses formed on the memory subarray of the semiconductor memory device according to Conventional Example 1 (when viewed from a top surface of the semiconductor memory device). In FIG. 12, reference numerals 1, 4 and 5 designate the memory subarray, the write-only data bus and the read-only data bus, respectively. The functions of these elements are mentioned above.
FIG. 13 is a schematic sectional view illustrating wiring of data buses of the semiconductor memory device according to Conventional Example 1 (a sectional view taken along the face perpendicular to each data bus line on the memory array (the face Vxe2x80x94V of FIG. 12)).
In the present specification (including each Conventional Example and Embodiment), RDB1, XRDB1, RDB2, XRDB2, RDB3 and so forth are read lines, and WDB1, XWDB1, WDB2, XWDB2 and so forth are write lines.
In the respective pairs of lines, RDB1 and XRDB1, RDB2 and XRDB2 and so forth, each pair transmits complementary signals which are 1-bit of read signal.
In the respective pairs of lines, WDB1 and XWDB1, WDB2 and XWDB2 and so forth, each pair transmits complementary signals which are 1-bit of write signal.
In FIG. 13, the read-only data bus and the write-only data bus are formed in a same metal layer and two lines of each pair are arranged adjacently to each other.
In FIG. 13, each line extends in the direction perpendicular to the sheet.
In this specification, the read line and write line in each Conventional Example and Embodiment are 1.5 xcexcm in thickness (width) and located at minimum 1.5 xcexcm intervals.
The write-only data bus and the read-only data bus are a 32 bits of complementary data bus and all lines are aligned within the bus width of 380 xcexcm.
The read-only data bus has 64 (32 pairs) read lines and the write-only data bus has 64 (32 pairs) write lines.
This allows stray capacitance between lines of each Conventional Example and Embodiment to be compared in the same conditions. The bus width of 380 xcexcm is calculated from the following equation:
1.5 xcexcmxc3x97{(64+64)+127}≈380 xcexcm
That is, 380 xcexcm is the narrowest bus width within which data buses are positioned in Conventional Examples 1 and 2.
While the demand for advanced micro-fabrication technique and high-performance semiconductor memory device grows, there has been a problem that performance of semiconductor memory device cannot be improved due to delay in working speed of data bus caused by increase in interference noise (including Miller noise) between read lines or write lines. The interference noise is generated by increase in wiring capacitance as well as coupling capacitance between lines.
As a conventional example, a semiconductor memory device having the structure that a write line and a read line are positioned alternately in a same layer is disclosed in patent publication for U.S. Pat. No. 2,508,245 (hereinafter referred to as Conventional Example 2). In this structure, in consideration that read data bus and write data bus do not operate concurrently, read lines and write lines are placed alternately, thereby to decrease interference noise such as Miller noise(caused by Miller capacitance)between read lines or write lines. This can achieve the semiconductor memory device with high-speed operating data bus.
With reference to FIGS. 1, 14 and 15, the DRAM of Conventional Example 2 will be described.
The semiconductor memory device of Conventional Example 2 has the same structure as that shown in FIG. 1. FIG. 1 has been already described above.
FIG. 14 is a schematic view illustrating data buses formed on the memory subarray of the semiconductor memory device according to Conventional Example 2 (when viewed from a top surface of the semiconductor memory device). In FIG. 14, reference numerals 1, 4 and 5 designate a memory subarray, a write-only data bus and a read-only data bus, respectively. The structure of these elements was explained referring to FIG. 1
FIG. 15 is a schematic sectional view illustrating wiring of data buses of the semiconductor memory device according to Conventional Example 2 (a sectional view taken along the face perpendicular to each line of data buses on the memory array (the face VIxe2x80x94VI of FIG. 14)).
As read lines RDB and XRDB and write lines WDB and XWDB are described referring to FIG. 13, their explanation will be omitted.
In FIG. 15, the read lines and the write lines are positioned alternately in a same metal layer. As shown in FIG. 15, in aligning data bus lines within the bus width of 380 xcexcm, an interval between a pair of lines (for example, RDB1 and XRDB1) becomes 4.5 xcexcm.
The stray capacitance between two lines in a pair depends on interval between the two lines except for a conductive part (width of a line intervening the two lines in a pair). Each line of data buses is in a precharged state during non-operating time. Therefore, an adjacent precharged line bus serves as a shield line between a pair of lines, thereby to eliminate any interference between the pair of lines. This can reduce interference noise such as Miller noise between read lines or write lines so that the semiconductor memory device can achieve high-speed operating data bus.
In order to operate the semiconductor memory device at higher speed, however, it is necessary to further reduce coupling capacitance and interference noise between read lines or write lines.
An objection of the present invention is to provide a semiconductor memory device that enables data buses to operate at high speed by reducing interference noise (including Miller noise) between data bus lines.
In semiconductor memories such as dual port RAM, write operation and read operation mix and a write-only data bus and a read-only data bus transmit a signal concurrently. In such semiconductor memories, interference noise between a write line and a read line also causes a problem. Another object of the present invention is to provide a semiconductor memory device such as dual port RAM which enables data buses to operate at high speed by reducing interference noise between a write line and a read line.
Further, given that write-only data bus becomes precharged at ground level and the write-only data bus is situated next to a VDD (power source) line, when dust generated during manufacturing process causes short-circuit between the write-only data bus and the VDD line, penetrating current between the GND (ground) line and the shorted VDD line occurs through the write-only data bus in precharged state, resulting in faulty penetrating current during standby.
In order to solve the above-mentioned problem, in the present invention, for instance, a read-only data bus and a VDD line are formed in one layer, a write-only data bus and a GND (VSS) line are formed in another layer, the read-only data bus become precharged at VDD level and the write-only data bus become precharged at GND level. This structure intends to provide a semiconductor memory device that causes no standby current failure even when short-circuit between adjacent lines occurs.
The present invention solves the above-described problem by means of the below-described configurations.
A semiconductor memory device according to an aspect of the present invention comprises a read-only data bus being formed in a first metal layer and having plural pairs of read lines precharged to an arbitrary voltage, two lines in a pair transmitting complementary read signals; and a write-only data bus being positioned in parallel with said read-only data bus, being formed in a second metal layer different from the first metal layer and having plural pairs of write lines precharged to an arbitrary voltage, two lines in a pair transmitting complementary write signals.
In the above-described semiconductor memory device according to another aspect of the present invention, the read-only data bus is formed on a memory array and transfers data amplified by a sense amplifier in a memory cell to peripheral circuit area; and the write-only data bus is formed on the memory array and transfers data from the peripheral circuit area to a memory cell.
In the above-described semiconductor memory device according to another aspect of the present invention, each two lines in a pair are positioned adjacent to each other and each line of the read-only data bus and each line of write-only data bus are arranged so as to substantially overlap one another in vertical direction.
In the above-described semiconductor memory device according to another aspect of the present invention, each two lines in a pair are positioned adjacent to each other and each line of the read-only data bus is arranged so as intervene between adjoining lines of the write-only data bus.
In the above-described semiconductor memory device according to another aspect of the present invention, two lines in a pair in the read-only data bus or the write-only data bus are positioned adjacent to each other, and interval between the two lines in a pair is narrower than interval between each two lines not in a pair.
In the above-described semiconductor memory device according to another aspect of the present invention, any ones of power source lines and ground lines are formed in a first metal layer and each line of them is arranged so as to intervene two lines not in a pair of the read-only data bus; and the other ones of power source lines and ground lines are formed in a second metal layer and each line of them is arranged so as to intervene two lines not in a pair of the write-only data bus.
In the above-described semiconductor memory device according to another aspect of the present invention, the read-only data bus is precharged to a same electrical potential as any ones of power source lines and ground lines formed in the first metal layer; and the write-only data bus is precharged to a same electrical potential as the other ones of power source lines and ground lines formed in the second metal layer.
A semiconductor memory device according to another aspect of the present invention, comprises a read-only data bus having plural pairs consisting of a first line and a second line precharged to an arbitrary voltage, two lines in a pair transmitting complementary read signals; and a write-only data bus being positioned in parallel with the read-only data bus and having plural pairs consisting of a third line and a fourth line precharged to an arbitrary voltage, two lines in a pair transmitting complementary write signals, wherein the first line and the third line are formed in a first metal layer, and the second line and the fourth line are formed in a second metal layer different from the first metal layer.
In the above-described semiconductor memory device according to another aspect of the present invention, the read-only data bus is formed on a memory array and transfers data amplified by a sense amplifier in a memory cell to peripheral circuit area; and the write-only data bus is formed on the memory array and transfers data from the peripheral circuit area to a memory cell.
In the above-described semiconductor memory device according to another aspect of the present invention, the first line and the third line are positioned alternately; the second line and the fourth line are positioned alternately; the second line in pair with the first line is arranged in substantially overlapping relation with the third line adjacent to the first line; and the fourth line in pair with the third line is arranged in substantially overlapping relation with the first line adjacent to the third line.
In the above-described semiconductor memory device according to another aspect of the present invention, interval between two lines in a pair of the read-only data bus is narrower than interval between two adjoining lines not in a pair of the read-only data bus, or interval between two lines in a pair of the write-only data bus is narrower than interval between two adjoining lines not in a pair of the write-only data bus.

Read only data bus and write only data bus forming in different layer metals

Matsushita Electric Industrial Co., Ltd.


Various embodiments are directed to ambidextrous firearm controls, including an ambidextrous bolt control assembly and/or ambidextrous magazine release and associated methods. The ambidextrous bolt control assembly may include a bolt catch configured to hingedly connect to a firearm to rotate between a disengaged position and an engaged position, the bolt catch may include a first bolt catch engagement button operable from a first side of the firearm and a first bolt catch release button operable from the first side of the firearm; an ambidextrous bolt catch engagement button operable from a second side of the firearm; and an ambidextrous bolt catch release button operable from the second side of the firearm; wherein the ambidextrous bolt catch engagement button and the ambidextrous bolt catch release button may each be separately movable relative to the firearm. The ambidextrous bolt catch assembly may further include an ambidextrous magazine release assembly.

Industrial and commercial applications may use firearms comprising ambidextrous firearm controls. In particular, a firearm comprising ambidextrous firearm controls may be used to enable user control of various firearm controls from either a left side or a right side of the firearm. Through applied effort, ingenuity, and innovation, Applicant has solved problems relating to ambidextrous firearm controls by developing solutions embodied in the present disclosure, which are described in detail below.


A pet washing apparatus is disclosed. The apparatus includes a base, a top member, side supports, and a flexible side wall. In various embodiments, a water line brings water in from a water source such as a sink faucet. The water line is attached to a nozzle. A drain tray is placed over the base so that water used within the apparatus drains through the drain tray into the base. A pump is provided in the base to pump water out of the base through a water exit line, for example, into a sink drain. The device is collapsible such that the drain tray, side support, and top member all collapse and fit within the base. Optionally, the base has a handle and wheels.

1. Field of the Invention
The present invention relates to an apparatus for washing a pet, and more particularly, to a convenient and useful pet washing apparatus.
2. Background
Various devices have been used for grooming or bathing pets. For example, U.S. Pat. No. 5,213,064, issued to Mondine et al., discloses an animal bath apparatus. The apparatus is shaped like a box. While the device could be used to bathe a pet from the top, it does not provide for drainage of used bath water. Furthermore, it is not collapsible and thus it is cumbersome to move around and takes up significant storage space.
U.S. Pat. No. 5,243,931, issued to McDonough, discloses a tub to be used for washing an animal. However, again, the device takes up significant space, and drainage is through the bottom only.
Numerous other apparatus have been proposed. However, none of them are particularly compact, nor do they provide a useful way to handle drainage issues.
Thus, there remains a need for a pet washing apparatus which is collapsible, compact, easily portable, and provides a convenient way to bathe a pet.


A clock includes a main body having a lower space and provided with a protruding post extended into the lower space, a face plate mounted on the main body and formed with a plurality of holes, a tumbler mounted in the lower space of the main body and rested on the protruding post, a top cover mounted on the main body to form an upper space, and a plurality of rolling balls mounted in the upper space and placed on the face plate. Thus, the clock has a playing function and can produce a figure arrangement variation.

1. Field of the Invention
The present invention relates to a clock, and more particularly to a clock having a playing function.
2. Description of the Related Art
A conventional clock comprises a main body, a face plate mounted on the main body, a time scale printed on the face plate, and a tumbler mounted on the main body and having a shaft extended through the face plate and provided with three pointers. However, the conventional clock only has a single function, thereby limiting the versatility of the conventional clock.


Systems and methods are provided for detecting an anomaly in a hidden portion of a first layer of a multi-layer structure. A monitoring element is provided on at least one exposed end of a fastener that extends through the multi-layer structure, and another monitoring element on an exposed portion of the first layer. With at least one of the monitoring elements, an inspection signal is introduced into the multi-layer structure including the hidden portion of the first layer. The inspection signal is then sensed with at least another one of the monitoring elements following propagation of the inspection signal through at least a portion of the multi-layer structure including the hidden portion of the first layer. Finally, an anomaly may be detected in the hidden portion of the first layer based upon the inspection signal that has been sensed.

A number of structures are formed of a plurality of layers that are stacked or otherwise laid one upon another to form a multi-layer structure. For example, air vehicles, such as aircraft, commonly include multi-layer structures to form various portions of the airframe. The multiple layers of a structure may be held together by one or more fasteners. In order to install a fastener, a hole may be drilled or otherwise formed through the multiple layers with a fastener thereafter being inserted through the hole. However, various anomalies may occur at or near the holes through which the fasteners extend, such as fatigue cracking due to the stress concentrations that may be present proximate the holes.
As a result of the multi-layer structure, at least portions of one or more of the layers that are proximate the hole through which the fastener extends may be hidden from view. For example, an intermediate layer of a multi-layer structure may be sandwiched between two outer layers which serve to hide the inner layer from view. By way of example, an air vehicle may include brackets mounted on longerons. The longerons may be mounted on bulkhead flanges which may, in turn, be covered by a skin. Each of these layers may be held together by one or more fasteners extending through holes that have been formed in the layers, e.g., the brackets, the longerons, the bulkhead flanges and the skin. As a result of the stacking of the various layers, portions of at least the longerons and the bulkhead flanges may be hidden from view.
Maintenance and repair personnel may desire to inspect a structure, such as an air vehicle, to identify anomalies such that the anomalies may be evaluated for repair, replacement or the like. However, the hidden layers of a multi-layer structure may not be visibly inspected and, instead, the multi-layer structure may need to be disassembled in order to view the hidden layers, such as to identify any anomalies that occurred at or near a hole through which a fastener extends. Such disassembly may be relatively labor intensive and may increase the cost and the time requirements for the inspection. Additionally, the reassembly of the structure following the inspection may also be problematic in that damage to the structure may be incurred during the reassembly process or portions of the structure may be reassembled incorrectly.
In an effort to facilitate the inspection of various structures, a variety of non-destructive evaluation ("NDE") techniques have been developed in which signals are transmitted into a structure with the signals that emerge from the structure then being evaluated in order to detect anomalies within the structure. However, NDE techniques may have difficulty in detecting anomalies in the hidden layers of a multi-layer structure due to the deleterious affect upon the signals that is created by the multiple interfaces between layers of the multi-layer structure. In addition, the thickness of a multi-layer structure may also adversely impact the ability to detect anomalies with NDE techniques where the anomalies lie within the hidden layers of the multi-layer structure.
As such, it may be desirable to provide an improved technique for inspecting the hidden layers of a multi-layer structure.

System and method for detecting an anomaly in a hidden layer of a multi-layer structure


An artificial blood has a trunk portion with both ends connected to blood vessels, and access branch portions and a shunt branch portion branched from the trunk portion. The access branch portions are disposed with a solid column-shaped access port that plugs these branch portions. The access port has a solid center portion and a tube-shaped peripheral portion disposed to surround the center portion. The peripheral portion is harder than the center portion and prevents the needle from deviating from the inside of the center portion. This enables a puncture to be easily made in a therapy in which a puncture is highly frequently made in a blood vessel.

In a blood extracorporeal circulation therapy such as hemodialysis and apheresis in which patient's blood is once taken out of a body and returned into the body again, it is necessary to frequently insert a needle into a blood vessel. If a puncture into a blood vessel is frequently performed, an aneurysm may be formed or vasoconstriction may occur. A blood access (blood vessel reaching method) has been proposed that uses an indwelling type apparatus capable of reducing the number of punctures into a blood vessel. In a blood access disclosed in Patent Document 1, a blood chamber connected through a cannula to a blood vessel includes a diaphragm, and a needle is inserted into the diaphragm to perform introduction of blood, etc., into the blood vessel, leading-out of blood from the blood vessel, etc., through this needle. Since the puncture is repeatedly made into the diaphragm, the damage to the blood vessel is alleviated.

Artificial blood vessel and access port of artificial blood vessel


An information processing device that carries out the processing of a fighting game in which a player-character is made to fight an opponent-character, the device including a first condition determination means that determines whether the player-character and the opponent-character, as a whole, have fulfilled a first condition during the fight; a second condition determination means that determines a character, among the player-character and the opponent-character, that has fulfilled a second condition during the fight; and a bonus awarding means that awards a bonus that can be used in the fight to a fulfilling character, among the player-character and the opponent-character, that fulfills the second condition after the fulfillment of the first condition. The first condition determination means sets a partial or a complete fulfillment of a given set of conditions as the first condition.

The present invention relates to an information storage medium, an information processing device, and a game system.
In many fighting games, a variety of parameters are assigned to each player-character and opponent-character and simple rules are established. For example, when a specific parameter (e.g., a stamina parameter (discussed later)) of a character reaches zero within a time limit, that character loses or, when the time limit has elapsed, the character for which the specific parameter is relatively lower loses. In such games, the player can advance through the battle by causing the player-character to perform required actions while predicting the actions of the opponent-character on the basis of a skill gauge (gauge that reflects the skill parameter (described later)) of the opponent-character displayed on the game screen. For example, a player of the fighting game described in JP-A-2001-000737 can apply a change to the combat power parameter of the player-character by performing a predetermined key operation after the player-character as completed a specific action.
However, in this case, the actions of the opponent-character can be easily predicted from the skill gauge and, consequently, strategies available to the player lack diversity and there is a need for measures to increase interest in the combat itself.

Information storage medium, information processing device, and game system


A weighted walker attachment system generally comprises a kit of weighted walker attachments that can be mounted to standard walker or other assistive perambulatory device for use in physical therapy and rehabilitation. A plurality of weighted attachments are provided and adapted to be mounted at a variety of locations on an assistive device. The weight of each attachment can be adjusted, as needed, for example, by adding or removing individual weighted plates mounted on a base plate that itself is removably mounted to the assistive device. In alternate kits, interchangeable weighted attachments can be provided in varying weights, distinguished by optical and/or tactile indicators, and selectively mounted on the assistive device, either as an accessory or in replacing a portion of the device, such as extensions provided on a walker's legs, in accordance with a therapeutic rehabilitation plan for an individual patient.

Weights on walkers and assistive devices have commonly been used in rehabilitation and physical therapy for diagnoses and diseases that effect motor planning, coordination, balance, body awareness, and stability. A common assistive walker device used in physical therapy is illustrated in FIG. 1, and generally comprises a supportive frame of generally light-weight tubular metal construction adapted to support the weight of a patient as they walk. Commonly seen diagnoses that have shown benefit from added weight on such an assistive device include Parkinson's, stroke, cerebellum disorders, medically-induced ataxia, and spinal cord injury. Proprioception sense has also been proven to decrease with age, movement disorders, neurological deficits and dementia. However, at the same time, the elderly often rely on their sense of proprioception as vision and vestibular functioning declines with age-related changes. Therefore, it is crucial to ensure a person is able to access this sensory system to remain independent.
The purpose of adding weights to the patient's legs (via ankle weights) or placing weights on walkers and assistive devices is to increase proprioceptive feedback to the affected side or sides (this could be right, left, front or center) in order for the brain to have increased awareness and ability to perform functional tasks with improved motor control. In turn, this approach has given the patient the ability to ambulate, transfer, and stand with an increased level of independence. Generally, weights can be adjusted (by either increasing or decreasing the weighted amount) with increased therapy and over the course of time as improvement is shown or needed. Heretofore, weight has been added to walker devices by taking pre-existing ankle weights and loosely adding them to the walker frame, secured, for example, by Velcro straps or tape.
Once a patient has shown benefit from weights on an assistive walker device with improved ability to ambulate and balance, the concern is that such improvement is unlikely to carryover once they return back to the community (e.g., back to their own homes and away from a rehabilitation setting). It is unsafe to suggest a patient use ankle weights without the supervision of a therapist as this poses as a fall risk and increases risk of skin tears. Placing ankle weights on a walker device seems easier; however, the barrier lies with the appearance, and also the patient's own ability, strength and dexterity to place ankle weights on and off of the walker accurately and appropriately. For example, some patients may have difficulty in managing the Velcro straps due to difficulty with fine motor coordination. If the patient is relying on weights on their ankles every time they stand and walk, the risk of falls, skin tears and the load of donning and doffing the weights increases. Additionally, some elderly patients may be hard-of-sight, and may have difficulty accurately placing the weights on a walker, and moreover, may no be able to tell which weight even to use. If the wrong weight is used, or mismatched weights are mounted on different sides of the walker, or the weights are not even properly attached to the walker, then there can be deleterious effects on the therapy and the patient's health.
Accordingly, what is needed is a weighted walker attachment system that is easy to use by therapists and patients alike to adjust the weight of a walker device for therapeutic and rehabilitation purposes. Additionally, there is a need for a weighted walker attachment system that can be easily mounted to and equally easily removed from the walker device. Additionally, there is a need for such a system whereby the weights on the walker can be easily adjusted in accordance with a therapy regime, and further where the different weights that can be used on a walker device can be easily identified so as to eliminate risk of the wrong weights being used. In general, an aim of the present invention is to provide weighted walker attachments that overcome the problems and drawbacks associated with prior art walker devices and weighted-assistance approaches, and therefore significantly improve the utility of walker devices in physical therapy and rehabilitation.


A sealing-object (4) is fixed to a base-object (10). The sealing-object comprises a through-hole (5). The objects are fixed to each other in the following manner. In a preparation step, a fixing layer (1, 2, 3) is provided between the base-object and the sealing-object. In addition an evacuation device (6) equipped with an evacuation channel (7) is placed onto the sealing-object. The through-hole of the sealing object has a first extremity opening out on the evacuation channel and a second extremity opening out on the fixing layer. In a fixing step, the fixing layer is heated which causes the fixing layer to release gas. The gas is at least partially evacuated via the through-hole of the sealing-object and the evacuation channel of the evacuation device.

The invention concerns a method of fixing a sealing-object to a base-object. The sealing-object and the base-object can be, for example, silicon wafers. This type of method physically protects an electrical circuit included in one of the silicon wafers. This type of protection is an advantage, for example, in the field of smartcards. 2. Description of the Related Art
The French patent application number 2 767 966 concerns a secured integrated circuit device. The device includes an active layer with a semiconducting material and circuits integrated with the semiconducting material. This active layer includes an active side on which there are contact studs. An additional layer is then Axed to this active layer via an intermediate fixing layer, for example a thermosetting plastic. This fixing layer is deposited in the viscous state. Apart from its bonding properties, it is resistant to the traditional solvents.
Generally, its properties of bonding and resistance to solvents are temperature activated. During this activation, redundant products are formed in the intermediate fixing layer. Some redundant products are products resulting from various intermediate chemical reactions occurring, in particular, as a result of this activation. Other redundant products are solvents, especially solvents required to ensure that activation occurs correctly.

Method of fixing a sealing object to a base object


Systems and methods for performing DNSSEC signing are described in which digital signature operations may be performed by a network accessible signing server that is configured to interact with a separate client application. Exemplary methods may include receiving a signing request at the signing server from the client application to sign first data. The signing server may determine an active KSK and/or an active ZSK for the first data. The first data may then be transmitted by the signing server to a digital signature modules, which may include, for example, a hardware support module, or software signing applications. The signing server may receive a digitally signed version of the first data from the digital signature module, and provide the signed first data to the client application.

The Domain Name System (DNS) is the part of the Internet infrastructure that translates human-readable domain names into the Internet Protocol (IP) numbers needed to establish TCP/IP communications over the Internet. That is, DNS allows users to refer to web sites, and other resources, using easier to remember domain names, such as "www.en.example.com," rather than the numeric IP addresses, such as "184.108.40.206," which are machine readable addresses used by software to communicate with computers on the Internet. Each domain name is made up of a series of character strings (labels) separated by dots. The right-most label in a domain name is known as the "top-level domain" (TLD). Examples of well-known TLDs are ".com"; ".net"; ".org." etc. Each TLD supports second-level domains, listed immediately to the left of the TLD, e.g., "example" in "www.example.com." Each second-level domain can support a number of third-level domains located immediately to the left of the second-level domain, e.g., "en" in "www.en.example.com." There can be additional level domains as well. For example, a domain with additional domain levels could be "www.landscape.photos.example.com."
It should be noted that a single IP address, e.g., one assigned to a single server, can support numerous domain names. That is, different domain names may resolve to the same server, that can then determine what content to provide based on the requested domain name and/or additional non-domain information. This is sometimes referred to as virtual hosting.
Additional non-domain information may be included in a Uniform Resource Identifier ("URI") structure that includes the domain name. For example, a "path" part is a sequence of segments separated by a forward slash ("/"). This information may be included immediately to the right of the domain name, such as the "blog" in "www.example.com/blog/today.htm," and may be used by a server or other receiving device to identify and deliver specific content or run particular code. Other examples of non-domain information may include queries and fragments, the specifics of which are understood by those of ordinary skill in the art and are not discussed in detail herein. Combinations of this information may be included in web page hyperlinks that navigate a user to another section of the same page or to another web page.
Thus, as can be seen in the various examples provided above, and as appreciated by those of skill in the art, a domain, such as the second level domain "example.com", may contain a variety of different Internet accessible information with different addresses and other means of identification.
The actual registration of domain names is performed by companies referred to as domain name registrars ("registrars"). Registrars register domain names with registries. For example, an end user submits to a registrar a domain name for registration and provides an IP address to which the domain name should resolve. The registrar communicates with the registry to create a registry database record that can be used to resolve the domain name to the IP address provided by the end user and indicates the identity of the registrar through which the domain name was registered. Except for the expiration of the domain name registration at the registry, typically only the registrar designated in the domain name record at the registry can modify or delete registry database information about a domain name. An end user can switch registrars by following certain domain transfer procedures. Registrars may also act as a hosting provider, or the end user may have the domain hosted by a separate third-party domain hosting service.
A zone file is a text file that describes a portion of the DNS called a DNS zone. A zone file is organized in the form of resource records (RR) and contains information that defines mappings between domain names and IP addresses and other resources. The format of zone files is defined by a standard, with each line typically defining a single resource record. A line begins with a domain name, but if left blank, defaults to the previously defined domain name. Following the domain name is the time to live (TTL), the class (which is almost always "IN" for "internet" and rarely included), the type of resource record (A, MX, SOA, etc.), followed by type-specific data such as the IPv4 address for A records. Comments can be included by using a semi-colon and lines can be continued by using parentheses. There are also file directives that are marked with a keyword starting with a dollar sign.
The DNS distributes the responsibility of assigning domain names and mapping those names to IP addresses by designating authoritative name servers for each domain. Authoritative name servers are assigned to be responsible for their particular domains, and in turn can assign other authoritative name servers for their sub-domains. This mechanism generally helps avoid the need for a single central register to be continually consulted and updated. The DNS resolution process allows for users to be directed to a desired domain by a reverse lookup process whereby the user enters the desired domain, and the DNS returns appropriate IP numbers. During the DNS resolution process, a request for a given domain name is routed from a resolver (e.g. a stub resolver) to an appropriate server (e.g. a recursive resolver) to retrieve the IP address. To improve efficiency, reduce DNS traffic across the Internet, and increase performance in end-user applications, the DNS supports DNS cache servers that store DNS query results for a period of time determined by the time-to-live (TTL) of the domain name record in question. Typically, such caching DNS servers, also called DNS caches, also implement the recursive algorithm necessary to resolve a given name starting with the DNS root through to the authoritative name servers of the queried domain. Internet service providers (ISPs) typically provide recursive and caching DNS servers for their customers. In addition, home networking routers may implement DNS caches and proxies to improve efficiency in the local network.
Although the distributed nature of the DNS provides significant advantages in terms of the efficiency of the overall system it also makes the system vulnerable to certain types of malfunctions and/or attacks at various nodes in the system. One particular problem that can occur is referred to as DNS cache poisoning. DNS cache poisoning occurs when data are introduced into a DNS name server's cache database that did not originate from authoritative DNS sources. This may result from deliberate attacks on a name server, or it may be an unintended result of, for example, a misconfigured DNS cache or improper software design of a DNS applications. Thus, DNS cache poisoning can result in (1) resolution requests failing, such as when inaccurate or misconfigured IP address information is provided, or (2) a requesting user's resolution request being directed to a malicious site that spoofs the genuine domain and is used to illicitly obtain information such as account passwords, or to distribute malicious content, such as computer worms or viruses, that are delivered to the requesting user.
The Domain Name System Security Extensions (DINSSEC) is a suite of Internet Engineering Task Force (IETF) specifications for securing certain kinds of information provided by the DNS as used on IP networks. DNSSEC provides for the signing of DNS-ready zone files, ensuring origin authentication and data integrity for DNS data, as well as authenticated denial of existence. In general, answers provided within DNSSEC are digitally signed, and, by checking the digital signature, a DNS resolver is able to check if the information corresponds to the information on the authoritative DNS server. DNSSEC uses public-key cryptography for the digital signatures and authentication. The DNSKEY record is authenticated via a chain of trust, starting with a set of verified public keys for the DNS root zone, which is a trusted third party.
To implement DNSSEC, several new DNS record types were created or adapted to use with DNSSEC, including RRSIG, DNSKEY, DS, NSEC, NSEC3 and NSEC3PARAM. For example, when DNSSEC is used, each authoritative answer to a DNS lookup will contain an RRSIG DNS record in addition to the record type that was requested. The RRSIG record is a digital signature of the answer DNS resource record set. The digital signature can be verified by locating the correct public key found in a DNSKEY record. The DS record is used in the authentication of DNSKEYs in the lookup procedure using the chain of trust. NSEC and NSEC3 records are used to provide the authenticated denial of existence responses for DNS records that do not exist.
The requirements of DNSSEC involve the use of different keys, stored both in DNSKEY records and from other sources to form trust anchors. There are, for example, Key Signing Keys (KSKs), which are used to sign other DNSKEY records, and Zone Signing Keys (ZSKs), which are used to sign other records. Because the ZSKs are under the control and use of a specific DNS zone, they can be switched more easily and more often. As a result, ZSKs can generally be much shorter (in terms of byte length) than KSKs, while still offering an acceptable level of protection.
Although protocols have been developed for the employment of DNSSEC, including the use of KSKs and ZSKs, there are numerous aspects of operating DNSSEC enabled domains, at the registrar and registry levels, that have not been addressed and/or optimized for large-scale use. For example, the ability to process large numbers of signatures in short periods of time, is limited to the common practices of using stand-alone signing systems and signing entire zones based on changes to the zone. Additionally, may solutions are limited to individual users, or a limited number of domains etc. that may be managed by a particular DNS provider. Accordingly, there are ongoing needs to further improve the functionality and/or efficiency of operations related to DNSSEC management and the signature functions required for DNSSEC records.


A gear shift control device for controlling a hybrid vehicle drive system including an engine, an automated transmission, a clutch, and a motor generator, includes a torque indication device for indicating a driver request torque determined in accordance with an operation amount of an accelerator operated by a driver, a power generation interruption device changing a vehicle state to an engine driven state using all of the engine torque when a preliminary gear shift condition is satisfied in a state where the engine drives a driving wheel and the motor generator is actuated to generate an electric power, and a gear shift control device reducing the engine torque and generating an assist torque by actuating the motor generator, disconnecting the clutch, and returning the clutch to a connected state after changing gear sets of the gear train when a gear shift condition of the automated transmission is satisfied.

Various known drive systems for hybrid vehicles including an engine and a motor as a drive source are practically implemented in accordance with widespread use of hybrid vehicles. For example, according to a known structure, an input shaft of an automated transmission is connected to an output shaft of an engine via a clutch, and a motor is connected between an output shaft of the automated transmission and driving wheels. According to the foregoing construction, a motor generator, which is a motor having an electric generating function, is most likely adopted as a motor, which allows not to be provided with a separate generator. Further, for example, an automated manual transmission (AMT), which is a manual transmission selectively engaging a set of gears among plural sets of gears and automated by an actuator. The AMT provided with a clutch at an input side excels in giving a feeling that a torque increases in accordance with an operation of an accelerator when transmitting the torque compared to a planetary gear type automated transmission provided with a torque converter at an input side.
It is preferable that the feeling that a torque increases in accordance with an operation of an accelerator when transmitting the torque is ensured during a gear shifting operation and a feeling that the vehicle is not accelerated in response to an accelerator operation is not generated even at a disconnected state of the clutch. JP2002-188716A (i.e., hereinafter referred to as Patent reference 1) discloses a power transmission apparatus for hybrid vehicle which eliminates a feeling that the vehicle is not accelerated in response to an accelerator operation during a gear shift operation. The power transmission apparatus disclosed in Patent reference 1 includes an internal combustion engine, a transmission, a clutch arranged between the internal combustion engine and the transmission, an electric motor arranged between the clutch and driving wheels, and a control portion. The control portion is configured to actuate the electric motor before disconnecting the clutch upon detecting a shift point. Thus, according to Patent reference 1, because the drive torque from the electric motor is transmitted even if the drive torque from the internal combustion engine is not transmitted due to the disconnection of the clutch, the driving wheels are not assumed to be in a completely driven state. Further, noises and vibrations because of mechanical shakiness are not generated when shifting gears, and a shift feel is enhanced because a feeling that the vehicle is not accelerated in response to an accelerator operation is eliminated during the gear shift operation.
According to the power transmission apparatus disclosed in Patent reference 1, a gear shift operation is relatively easy and effects can be readily attained in a case where the electric motor is not in operation immediately before shifting gears, however, is not completely flawless. For example, according to a hybrid vehicle to which a motor generator is mounted in place of the electric motor, in a case where a state of charge of a battery declines, the vehicle travels while generating electric power. In those circumstances, modes of the motor generator is switched from a power generation mode to an assist mode during the gear shift operation, a drive torque transmitted to the driving wheels is assumed to be discontinuous, which may generate shift shock. Further, when performing a gear shift operation in a case where the motor generator performs a drive assist by adding an assist torque of the motor generator to an engine torque for the purpose of enhancing fuel economy under a state where state of charge of the battery is favorable, the drive torque is assumed to be discontinuous so that the shift shock may be generated.
A need thus exists for a gear shift control device for a hybrid vehicle drive system which is not susceptible to the drawback mentioned above.

Gear shift control device for hybrid vehicle drive system


Computer implemented methods for access control for a restricted resource in a computer system and related methods train a hierarchical temporal memory and use cryptocurrency allocations and blockchain records to determine whether resource consumers are authorized or unauthorized to access the restricted resource.

Access control for computer systems, services and resources is based on a defined set of access rights for a user, consumer or class of user or consumer. Notably, users or consumers can include other computer systems, software components or automated entities that make use of, or consume, services and/or resources. These access rights can be constituted as access control rules for a user or class that must be defined to determine permitted and/or non-permitted actions by a user such as access to resources and/or services.
Defining access control rules requires considerable effort to ensure all aspects of access control and behavior management are considered. Thus, rules can be defined on a per-resource or service basis, a per-user or class basis, and per-permission or user/consumer right basis. The multi-dimensional considerations in defining these rules therefore presents a considerable burden that it would be advantageous to mitigate.

Hierarchical temporal memory for expendable access control

British Telecommunications Public Limited Company


A liquid crystal display (LCD) device and a method of driving the same applies dummy pixel signals each representing a substantially identical brightness level during a blanking period, wherein the horizontal stripe phenomenon is substantially prevented from being generated due to differences in capacitive coupling between liquid crystal cells and adjacent data line.

1. Field of the Invention
The present invention relates to liquid crystal display (LCD) devices. More particularly, the present invention relates to a LCD device and a method of driving the same, wherein generation of a horizontal stripe phenomenon may be prevented.
2. Description of the Related Art
Generally, liquid crystal display (LCD) devices control light transmittance characteristics of liquid crystal material in accordance with applied electric fields. Accordingly, LCD devices typically include an LCD panel having a plurality of liquid crystal cells arranged in a matrix pattern, and drive circuits to drive the plurality of liquid crystal cells.
FIG. 1 illustrates a related art liquid crystal display (LCD) device.
Referring to FIG. 1, the related art includes an LCD panel 12 having a plurality of liquid crystal cells 20 arranged in a matrix pattern, a gate diver 14 for driving a plurality of gate lines GL1 to GLn, a data driver 16 for driving a plurality of data lines DL1 to DLm, and a timing controller 18 for controlling the gate and data drivers 14 and 16, respectively. The LCD panel 12 further includes a plurality of thin film transistors (TFTs) formed at crossings of the plurality of gate and data lines GL1 to GLn and DL1 to DLm, respectively, wherein each of the TFTs is connected to a corresponding liquid crystal cell 20.
Upon driving the plurality of liquid crystal cells 20, the gate driver 14 sequentially applies scan signals to the plurality of gate lines GL1 to GLn to sequentially drive rows of liquid crystal cells 20. Accordingly, the scan signals include gate high and low voltages (VGH) and (VGL), respectively. Whenever the gate high voltage (VGH) is applied to a gate line (GL), TFTs within the driven row of liquid crystal cells are turned on and pixel signals, applied by the data driver 16 to each of the data lines DL1 to DLm, are transmitted to the driven row of liquid crystal cells 20. Whenever the gate low voltage (VGL) is applied to a gate line (GL), TFTs within the driven row of liquid crystal cells 20 are turned off, wherein a voltage corresponding to a pixel signal remains charged within the liquid crystal cell 20.
Each liquid crystal cell 20 can be equivalently represented as a liquid crystal capacitor (Clc) including a common electrode capacitively coupled to a pixel electrode by liquid crystal material having anisotropic dielectric properties, wherein the pixel electrode is connected to a TFT. Each liquid crystal cell 20 further includes a storage capacitor (Cst) formed between a pixel electrode and a pre-stage gate line for retaining a voltage associated with a pixel signal until a subsequent pixel signal is charged to the liquid crystal cell 20. Once a pixel signal is applied from a data line (DL), a turned-on TFT applies a voltage associated with the pixel signal to the pixel electrode to generate electric field between the pixel and common electrodes. In response to the generated electric field, a molecular orientation of the liquid crystal material is manipulated such that light transmittance characteristics of the liquid crystal cell are controlled. Moreover, gray scale values of light are realized by the liquid crystal cell by adjusting the pixel signal voltage.
The gate driver 14 sequentially applies the gate high voltage (VGH) to the plurality of gate lines GL1 to GLn in response to gate control signals (GSP, GSC, GOE) outputted from the timing controller 18. More specifically, the gate driver 14 generates a shift pulse by shifting a gate start pulse (GSP) in accordance with a gate shift pulse (GSC). Next, the gate driver 14 applies the gate high voltage (VGH) to a predetermined gate line (GL) during each horizontal period in response to the gate shift pulse (GSC). During operation, the gate driver 14 applies the gate high voltage (VGH) only during an enable period of a gate output enable signal (GOE). During periods of time when the gate high voltage (VGH) is not applied, however, the gate driver 14 applies the gate low voltage (VGL) to the gate lines GL1 to GLn.
The data driver 16 applies pixel signals, specific for each gate line to which the gate high voltage (VGH) is applied, simultaneously to each of the data lines DL1 to DLm in response to data control signals (SSP, SSC, SOE, POL) outputted from the timing controller 18. More specifically, the data driver 16 generates a sampling signal by shifting a source start pulse (SSP) in accordance with a source shift clock (SSC). Next, the data driver 16 sequentially receives and latches digital pixel data (R,G,B) outputted from the timing controller 18 in response to the sampling signal. The data driver 16 then converts the digital pixel data (R,G,B), latched in correspondence with the gate line to which the gate high voltage (VGH) is applied, into analog pixel signals and applies the analog pixel signals to the data lines DL1 to DLm during the enable period of the source output enable signal (SOE). More specifically, the data driver 16 converts the digital pixel data (R,G,B) into analog pixel signals using gamma signals outputted from a gamma voltage generator (not shown). The data driver 16 also converts the digital pixel data (R,G,B) into positive and negative polarity pixel signals in response to a polarity control signal (POL). For example, in response to the polarity control signal (POL), the data driver 16 inverts the polarity of the pixel signal based on a columnar arrangement of the liquid crystal cells 20 to drive the liquid crystal display panel 12 according to a dot inversion system.
As mentioned above, the timing controller 18 controls the gate and data drivers 14 and 16 by generating the gate control signals (GSP, GSC, GOE) and the data control signals (SSP, SSC, SOE, POL), respectively. Additionally, the timing controller 18 arranges the pixel data (R,G,B) and applies the arranged digital pixel data to the data driver 16.
As described above, liquid crystal cells 20 within the related art LCD display can be driven using an inversion driving method such as a frame inversion, line (column) inversion, or dot inversion method to improve a picture quality of the LCD device. Compared to other inversion driving methods, the dot inversion driving method provides an excellent picture quality. However, and as shown with reference to FIG. 2, use of the dot inversion driving method can generate defects, such as horizontal stripes, within the LCD panel 12. As described in greater detail below, the horizontal stripe phenomenon occurs due to the presence of first and second parasitic capacitors Cdp1 and Cdp2 formed between pixel electrodes 20 of liquid crystal cells A and B and preceding and succeeding ones of adjacent data lines (e.g., data lines DLk and DLk+1).
The horizontal stripe phenomenon, generated when the liquid crystal display panel is driven according to the dot inversion driving method, will now be explained in greater detail with reference to FIGS. 3 to 5.
FIG. 3 illustrates charging characteristics of vertically adjacent liquid crystal cells with respect to pixel signals applied to the kth data line shown in FIG. 2. FIG. 4 illustrates charging characteristics of vertically adjacent liquid crystal cells with respect to pixel signals applied to the (k+1)th data line shown in FIG. 2. FIG. 5 illustrates charging characteristics of vertically adjacent liquid crystal cells with respect to pixel signals applied to the kth and (k+1)th data lines shown in FIG. 2.
Referring to FIGS. 2 to 5, during a first horizontal period, a first pixel signal (−Vp), having a negative polarity (−) with respect to the common voltage Vcom, is applied to the kth data line (DLk) while a first pixel signal (+Vp), having a positive polarity (+) with respect to the common voltage Vcom is applied to the (k+1)th data line (DLk+1). The brightness level represented by the first positive polarity pixel signal (+Vp) is relatively higher than the brightness level represented by the first negative polarity pixel signal (−Vp). Simultaneously with the application of the first negative and positive polarity pixel signals −Vp and +Vp, a first thin film transistor (TFT1), connected to the first gate line (GL1), is turned on in response to a scan pulse (not shown) applied to the first gate line (GL1). Accordingly, a first negative pixel voltage Vp1, associated with the first negative polarity pixel signal (−Vp), is charged to the first liquid crystal cell (A) connected to the first gate line (GL1) from the kth data line (DLk).
Subsequently, during a second horizontal period (H2), a second pixel signal (+Vp), having a positive polarity (+) with respect to the common voltage Vcom, is applied to the kth data line (DLk) while a second pixel signal (−Vp), having a negative polarity (−) with respect to the common voltage Vcom is applied to the (k+1)th data line (DLk+1). The brightness level represented by the second negative polarity pixel signal (−Vp) is relatively higher than the brightness level represented by the second positive polarity pixel signal (+Vp). Simultaneously with the application of the second positive and negative polarity pixel signals +Vp and −Vp, a second thin film transistor (TFT2), connected to the second gate line (GL2), is turned in response to a scan pulse (not shown) applied to the second gate line (GL2). Accordingly, a second positive pixel voltage Vp2, associated with the second positive polarity pixel signal (+Vp), is charged to the second liquid crystal cell (B), connected to the second gate line (GL2), from the kth data line (DLk).
As a result of driving the related art LCD panel as described above, the first negative pixel voltage Vp1 is capacitively affected by the second positive polarity pixel signal (+Vp) applied to the kth data line (DLk) via the first parasitic capacitor (Cdp1) and by the second negative polarity pixel signal −Vp applied to the (k+1)th data line (DLk+1) via the second parasitic capacitor (Cdp2) during the second horizontal period (H2). Accordingly, a value of the first negative pixel voltage Vp1 changes during the second horizontal period (H2). Since an absolute value of the second negative polarity pixel signal −Vp applied to the (k+1)th data line (DLk+1) is relatively large, the capacitance of the second parasitic capacitor (Cdp2) is also relatively large, thereby increasing the magnitude of the first negative pixel voltage Vp1 within the first liquid crystal cell (A).
Moreover, during a third horizontal period (H3), a third negative polarity pixel signal (−Vp) is applied to the kth data line (DLk) to charge a third liquid crystal cell (not shown) while a third positive polarity pixel signal (+Vp) is applied to the (k+1)th data line (DLk+1). The brightness level represented by the third positive polarity pixel signal (+Vp) is relatively higher than the brightness level represented by the third negative polarity pixel signal (−Vp). Accordingly, the first negative pixel voltage Vp1 and the second positive pixel voltage Vp2 are both capacitively affected by the third negative and positive polarity pixel signals −Vp and +Vp respectively applied to the kth and (k+1)th data lines (DLk) and (DLk+1), respectively, via the first and second parasitic capacitors Cdp1 and Cdp2, respectively, during the third horizontal period (H3). Accordingly, a value of the first negative and second positive pixel voltages Vp1 and Vp2 change during the third horizontal period (H3). Since an absolute value of the third positive polarity pixel signal +Vp applied to the (k+1)th data line (DLk+1) is relatively large, the capacitance of the second parasitic capacitor (Cdp2) is also relatively large, thereby positively decreasing the magnitude of the first negative pixel voltage Vp1 and positively increasing the magnitude of the second positive pixel voltage Vp2.
As can be seen from the discussion above, the various positive and negative polarity pixel signals, charged within each liquid crystal cell, capacitively affect existing positive and negative pixel voltages, previously charged via the kth and (k+1)th data lines (DLk) and (DLk+1) through the first and second parasitic capacitors Cdp1 and Cdp2 within each liquid crystal cell. Moreover, due to the presence of the aforementioned polarity control signals (POL) applied to the kth and (k+1)th data lines (DLk) and (DLk+1), the polarity of the capacitance within the parasitic capacitors (Cdp1 and Cdp2) is inverted during each horizontal period (H). As a result, the various pixel voltages charged within each liquid crystal cell can become offset.
During the data apply period (DAP) of a first frame (1F), pixel signals are applied to the kth and (k+1)th data lines (DLk and DLk+1) in accordance with the dot inversion method. Due to the aforementioned offset, changes in first and second effective voltages (EVa and EVb) of the first and the second liquid crystal cells A and B, respectively, are substantially the same.
During a blanking period (BP) succeeding the data apply period (DAP), however, the kth and (k+1)th data lines (DLk and DLk+1) are placed in a floating state wherein the first and second liquid crystal cells A and B are capacitively coupled with pixel signals applied during the nth horizontal period (Hn) of n number of horizontal periods. Accordingly, values of the first (negative) and second (positive) pixel voltages Vp1 and Vp2 associated with the nth horizontal period are maintained during the blanking period.
For example, during the nth horizontal period, an nth negative pixel signal is applied to the kth data line (DLk) while an nth positive pixel signal is applied to the (k+1)th data line (DLk+1). The brightness level represented by the nth positive polarity pixel signal (+Vp) is relatively higher than the brightness level represented by the nth negative polarity pixel signal (−Vp). Accordingly, the nh negative and positive pixel signals are applied to the kth and (k+1)th data lines (DLk and DLk+1), respectively, during the blanking period (BP). As a result, the first (negative) and second (positive) pixel voltages Vp1 and Vp2 are capacitively affected by the nth pixel signals. More specifically, the magnitude of the first negative pixel voltage Vp1 is positively decreased a first amount due to the first parasitic capacitor (Cpd1) while the magnitude of the first negative pixel voltage Vp1 is negatively increased a second amount, greater than the first amount, due to the second parasitic capacitor (Cpd2). Further, the magnitude of the positive pixel voltage Vp2 is negatively decreased a first amount due to the first parasitic capacitor (Cpd1) while the magnitude of the first negative pixel voltage Vp1 is positively increased a second amount, greater than the first amount, due to the second parasitic capacitor (Cpd2). Since an absolute value of the first negative pixel voltage (Vp1) decreases during the blanking period (BP) while an absolute value of the second positive pixel voltage (Vp2) increases during the blanking period (BP), the intensity to which the first liquid crystal cell (A) transmits light differs compared to the intensity to which the second liquid crystal cell (B) transmits light.
Based on the values of the pixel signals Vp applied to the first and second liquid crystal cells (A) and (B) via the kth data line DLk, and based on the first (negative) and second (positive) pixel voltages Vp1 and Vp2, respectively, charged within the first and second liquid crystal cells (A) and (B), respectively, during the blanking period (BP), the effective pixel voltages EVa and EVb of the first and second liquid crystal cells (A) and (B), respectively, are determined by the following equations:EVa=(1−t)×Vp+t×Vp1EVb=(1−t)×Vp+t×Vp2,wherein t represents the duration of the blanking period (BP) within of one frame period (1F) and (1−t) represents the duration of the data apply period (DAP) within one frame period (1F).
Accordingly, the intensity to which an ith horizontal having the first liquid crystal cell (A) line transmits light differs compared to the intensity to which an (i+1)th horizontal line having the second liquid crystal cell (B) transmits light during the blanking period (BP) and the horizontal stripe phenomenon is generated.
Referring to FIG. 6, the effect of the horizontal stripe phenomenon is similar to the effect of displaying a green (G) pattern along a vertical direction. Accordingly, the picture quality in the related art LCD device is deteriorated. Moreover, the effect of the horizontal stripe phenomenon becomes more apparent as the duration of the blanking period within the frame increases, as the difference between absolute values of the pixel signals supplied to adjacent ones of data lines increases, and as differences in the capacitance values of the first and second parasitic capacitors Cdp1 and Cdp2 increases.

Liquid crystal display and method of driving the same


A steam stop safety mechanism for a portable steam cleaner prevents discharge of steam at the cleaner nozzle when attaching and disconnecting attachments, even if the cleaner trigger is in a locked open position. The mechanism includes a steel pin that is displaced in an extended position against a shoulder in the nozzle to prevent pressurized steam from escaping the nozzle. Attachment couplings include a pin retractor plate with a central hub that pushes the pin away from the shoulder to allow the steam to flow through openings in the retractor plate and out a concentrator or attachment hose that has a trigger to release steam as desired.

The invention relates generally to devices for applying steam to objects, and more particularly to steam cleaner including a safety feature that prevents inadvertent release of steam when attaching or removing a hose, concentrator nozzle, or other accessory.
Steaming devices used to apply steam to household objects are well known. The uses of the devices vary widely, and may include the application of steam to drapes or other fabrics to ease wrinkles, and the application of steam to objects to assist in cleaning the objects.
Typical steam devices utilize a heating element to heat water. The heated water generates steam, which may be directed towards its intended destination through a nozzle which controls application of the steam. Variation of the shape and size of the nozzle allows for preferred distribution of generated steam to an object to be cleaned. The nozzles may typically be disconnectable from the steam generator to allow different nozzles to be utilized, based on the object to be steamed. The nozzle may be either closely coupled to the steam generator, or located at a distance from the steam generator, requiring tubing or other steam transfer structures to be interconnected between the steam generator and the discharge nozzle. Typically, it is beneficial to provide suitable connectors between the steam generator and the nozzle to allow either the nozzle to be connected to the steam generator, or to allow the interpositioning of transfer tubes or hoses between the steam generator and the nozzle.
Unregulated release of steam generated by a steam generator reduces the efficiency with which the device may be operated. Such inefficiency arises from the generation of steam when the steam is not being applied to an object to be steamed. This inefficiency increases the operating cost of the device, and decreases the utility of the device.
Manually operated steam release valves have been introduced between the steam generator and the discharge nozzle. However, such valves are often rendered inoperative by the user, such as by locking the steam release valve in an open position. A device to allow the operator to lock the discharge valve in an open position is often provided on the device, such that an operator would not need to retain manually the steam release valve in an open position during protracted periods of steaming.
Thus, notwithstanding the wide variety of steam generating appliances available, there exists the need to restrict flow of steam when a nozzle or steam hose is connected or disconnected from the device.


A compact, lightweight electric motor driven compressor suitable for an air conditioning system using a CO.sub.2 refrigerant is disclosed. The thickness of a motor casing is reduced by using the gaps formed in the motor portion in a motor casing as a part of a low-pressure intake chamber, while forming a part of the discharge chamber by utilizing the annular gap between the inner surface of a pump casing and the outer surface of a compressor portion. In the case where CO.sub.2 refrigerant is used, the compressor portion can be reduced in size and therefore a dead space is generated due to the difference in size with the motor casing. Since this dead space is used as a discharge chamber, the capacity of the discharge chamber can be increased to suppress the discharge pulsation.

1. Field of the Invention
The present invention relates to an electric motor driven compressor adapted to be used as a refrigerant compressor in an automotive air conditioning system or, in particular, to an electric motor driven compressor suitable for CO.sub.2 as a refrigerant.
2. Description of the Related Art
In an air conditioning system for an electric motor driven vehicle such as an electric car or a home-use air conditioning system, it has been general practice to use freon gas, such as R134a or the like, as a refrigerant for the refrigeration cycle. Also, a refrigerant compressor used for compressing the refrigerant in the refrigeration cycle of these air conditioning systems is disclosed in JP-A-65580, for example, as what is called the "electric motor driven compressor" in which a motor portion and a compressor portion including a scroll-type compressor are integrally built in a common hermetic casing.
In the electric motor driven compressor, an intake chamber and a discharge chamber or other chambers are formed in the internal space of a casing in which the motor portion is arranged. If it is assumed that an intake chamber is formed in the internal spacing of the motor casing of an electric motor driven compressor of a conventional air conditioning system using the refrigeration cycle with the freon gas or the like as a refrigerant, generally, in the refrigeration cycle in which a flexible pipe such as a rubber hose is not used, the body or the like parts of the automotive vehicle are liable to develop noises and vibrations due to the effect of the discharge pulsation of the compressor unless the discharge chamber of the electric motor driven compressor has a sufficiently large capacity. The result would be an increased bulk of the pump portion, and a larger capacity of the discharge chamber would result in an increased bulk of the electric motor driven compressor as a whole.
In the case where the internal spacing of the motor casing is used as a discharge chamber, on the other hand, the motor casing is regarded as a pressure vessel, and therefore, a high pressure resistance value is required according to the law and regulations. Therefore, the thickness of the motor casing is required to be increased. The problem in this case is that the electric motor driven compressor would become not only bulky but also heavy. Further, in the case where carbon dioxide (CO.sub.2) is used as a refrigerant, the operating pressure, i.e. the discharge pressure of the refrigerant compressor is about ten times as high as that for a freon refrigerant. This problem is therefore not negligible.


A needle shield for retainers enclosing suture-needle assemblies constructed of a fibrous material and foldable about at least two score lines to provide a protective device against needle damage, accidental sticking of the user's fingers, and puncture of the package within which the retainer is packaged.

1. Field of the Invention
The present invention relates to surgical suture-needle packages, and more particularly to a needle shield device for protecting the tip of the needles from damage and to eliminate the possibility of accidental sticking of a person's finger by the needles, as well as to prevent puncturing of the sterile package in which the needles are enclosed during storage and handling.
2. Discussion of the Prior Art
Packaging devices for needles and suture needle assemblies which include protective flaps or covers are well known in the art. These packages generally include a fold over flap or cover which encloses the needles or the needle tips in the package. In many cases, the flap is integrally formed as part of the package so that the flap or cover comprises a tear away portion which exposes the needles upon opening of the package.
The packaging of sutures, particularly sutures having a needle positioned on at least one end of the suture, requires special consideration to eliminate the possibility of puncturing of the sterile package by the needle enclosed therein, as well as to protect a surgeon or surgical team member from accidental sticking during handling while opening the package. It is also desirable to protect the needles themselves after the package is open against damage to the tips.
Typically, the suture is wound on a retainer prior to enclosure within a sterile, moisture-impervious outer package. The retainer may comprise any containment device, and generally is constructed of a fibrous, somewhat rigid material such as paperboard, pressed paper, or a cardboard material. The retainer may be formed as a series of panels which are foldable over each other to secure the suture between the panels. In most cases, the needles are either loosely positioned between the panels or latched to a panel and folded between the panels with the sutures. Examples of retainers which fold a series of panels over onto themselves to secure the sutures and needles therebetween are disclosed in U.S. Pat. No. 3,136,418 to Stacy et al. and U.S. Pat. No. 3,939,969 to Miller et al.
Another type of suture retainer is constructed as a two piece device having a molded plastic bottom tray which includes a coiled passageway. The suture lays in the passageway, and the entire tray is covered by a top cover or layer of a sheet-like material. When needles are provided on the sutures, the needles are usually secured outside the retainer; that is, the sutures are in the passageway of the bottom tray and covered by the top sheet, while the needles are external to the retainer and must be secured by some additional means. Usually, the needles are positioned in a holding member such as a foam needle park. An example of such a retainer is disclosed in U.S. Pat. No. 3,338,401 to Regan, Jr.
In order to maintain the sterility of such a device, the retainer having the needles attached thereto are further packaged in a moisture-impervious package, constructed of metal foil, plastic film or other suitable materials. A disadvantage to this arrangement lies in the fact that the sharp needles directly rest against the inner surface of the outer package, and may puncture the outer package during storage, handling, etc. This will of course destroy the sterility of the suture and needle assembly, and may expose the surgeon or surgical assistant to a hazard involving accidental sticking.
Several tear away type needle covers for use with surgical suture-needle assembly packages are provided in the prior art. These packages generally comprise a panel having either perforations or score lines which facilitate tearing a portion of the panel from the package to expose the needles after the package is opened. After the tear away cover or flap is removed, the needle and suture assembly may be removed from the package in the conventional manner.
In the prior art, several packages having tear away cover flaps are disclosed, such as U.S. Pat. No. 4,063,638 to Marwood. The package disclosed in Marwood comprises a three panel package, where the suture is wound and held at the center panel and the needle is held in an outer panel. A panel having the tear away flap is provided on the outer panel opposite the needle retaining panel, and the tear away flap is folded over the sutures followed by the needle retaining flap. Upon opening the package, the flap is torn away, thus revealing the needle so that the needle may be removed in the conventional manner.
Another type of package prevalent in the prior art provides a fold over flap which covers the needles within the package. When the package is opened, the fold over flap is unfolded to reveal the needles os that the needles may be removed in the conventional manner. Such a device is disclosed in U.S. Pat. No. 4,574,948 to Huck et al. Huck et al. provides a packaging device in which the suture is secured on one panel of the package and the needles are secured on a second panel. A fold over flap is provided to cover the needles to prevent sticking of the user and to prevent damage to the needle tips. As the package is opened, the fold over flap is unfolded to reveal the needles so that the needles may be removed in a conventional manner. A similar type device is disclosed in U.S. Pat. No. 4,708,241 to Black, deceased.
The devices disclosed in the prior art suffer from several disadvantages in which the risk of accidental sticking of the needle into the fingers of the user is not significantly reduced or eliminated, and further, many of these devices suffer the disadvantage in that the cost of packaging is increased due to the necessity for additional packaging material as well as increasing the number of packaging steps during assembly.
Surgical suture-needle retainers and needle packages are generally constructed of a material which resists folding and bending and which is strong enough to hold a coiled suture in place without the risk of the suture unraveling during shipment. The retainer must also be rigid enough to resist bending or folding to eliminate the risk of creasing the suture during shipment, so that when the retainer is opened the suture may be removed from the package without creases or bends. There is significant emphasis in the surgical suture industry placed on the "memory" retention of the suture material, so that the suture retains its original shape upon removal from the retainer with a minimum of bends and creases, even after extended periods of time within the retainer. In view of this, many of the retainers disclosed above which provide a needle retaining member which is folded over the package increase the amount of bends in the suture material during packaging, which may lead to an undesirable suture-needle assembly upon removal from the retainer.
A further disadvantage of the prior art retainers is that in using the retainer itself to protect the needles, such as those retainers disclosed above having a tear away portion, there is a requirement that additional packaging material must be provided to cover the needle given the fact that many of these retainers employ rigid panels, sometimes in laminate form, the cost of packaging is necessarily increased to provide the needle cover. In addition, the step of forming the retainer material must include the addition of score lines or perforations to facilitate the tear feature to expose the needles.
An additional disadvantage to these fold over devices lies in the face that the needles are hidden from view until that portion of the retainer is either torn away or unfolded to reveal the needles. Consequently, the user is at risk of accidentally sticking himself with the needles since he cannot see the needles during the tear away or unfolding step.
The novel needle shield device for surgical retainers and packages having needles or suture-needle assemblies of the present invention obviates the disadvantages encountered in the prior art and provides a universal needle shield device for use with any surgical needle or suture-needle retainer or package. The shield of light weight material and provides the user with protection against sticking while further providing protection for the needle tips against damage. The shield further protects the outer sterile package in which the retainer is enclosed from inadvertent puncture. The needle shield of the present invention may be used with any surgical needle or suture-needle assembly package, and eliminates the requirement for providing additional packaging material and the requirement for complex folding arrangements of the rigid retainer material to cover the needles.

Needle shield device for surgical packages


A quick connector assembly has a female housing with a hair pin style retaining clip to retain a beaded conduit therein. The female housing includes a pair of slots forming ramped surfaces on the housing to enable legs of the retainer to be transversely positioned within the axial bore of the female housing to retain male fittings therein.

The present invention relates to quick connector assemblies and, more particularly, to quick connector assemblies having female housings with ramped surfaces adapted to receive hair pin type retaining pins to retain male fittings within the housings.
In manufacturing fields, such as automotive, trucks, or the like, it is customary to employ quick disconnect devices to connect conduits or the like together. While conduits, such as piping, can be connected in a variety of ways, which include threaded couplings for efficient assembly of the mechanisms, it is desirable to have available a fluid coupling which can be attached very expeditiously but which at the same time, once attached, is substantially fail safe. Various types of couplings have been provided to be utilized in connecting of conduits.
These couplings are illustrated by the following U.S. patents. They are U.S. Pat. Nos. 951,283 issued to P. Krischer on Mar. 8, 1910; 2,021,241 issued to A. W. Mall on Nov. 19, 1935; 2,535,016 issued to J. M. Launder on Dec. 19, 1950; 2,772,898 issued to H. W. K. Sealer on Dec. 4, 1956; 3,121,583 issued to C. A. Damm on Feb. 8, 1984; 3,149,362 issued to C. B. Smithson on Sept. 22, 964; 3,154,327 issued to R. D. Rothschild on Oct. 27, 964; 3,215,455 issued to E. J. H. Fiala et al on Nov. 2, 1965; 3,268,260 issued to A. Snipe on Aug. 23, 1966; 3,314,696 issued to G. R. Ferguson et al on Apr. 18, 1967; 3,450,424 issued to J. V. Calisher on June 17, 1969; 3,471,186 issued to W. K. Luebbert et al on Oct. 7, 1969; 3,490,795 issued to G. Hennlich on Jan. 20, 1970; 3,534,988 issued to J. W. Lindsey on Oct. 20, 1970; 3,538,940 issued to C. H. Graham on Nov. 10, 1970; 3,584,902 issued to G. N. Vyse on June 15, 1971; 3,637,240 issued to E. Meier on Jan. 25, 1972; 3,698,747 issued to Wing et al on Oct. 17, 1972; 3,753,582 issued to C. H. Graham on Aug. 21, 1973; 3,767,234 issued to Weirich et al on Oct. 23, 1973; 3,842,870 issued to W. R. Burgess on Oct. 22, 1974; 3,973,791 issued to Porta et al on Aug. 10, 1976; 4,234,262 issued to Nakai et al on Nov. 18, 1980; 4,260,184 issued to Greenawalt et al on Apr. 7, 1981; 4,423,891 issued to W. H. Menges on Jan. 3, 1984; 4,431,218 issued to Paul, Jr. et al on Feb. 14, 1984; 4,524,995 issued to D. D. Bartholomew on June 25, 1985; 4,537,427 issued to H. M. Cooke on Aug. 27, 1985; 4,570,980 issued to S. H. Goward on Feb. 18, 1986; 4,772,052 issued to E. W. Morain on Sept. 20, 1988.
In several of the above patents, the retaining clip is positioned onto the housing after the male conduit has been inserted. Thus, the retainer functions as a staple or the like to retain the conduits together.
While the above patents appear to perform satisfactorily for their intended purpose, designers are always striving to improve the field.
The present invention provides the art with a hair pin style retainer which has flexible legs enabling spreading of the retainer legs to provide for insertion and removal of the male conduits. The legs also retain the male conduits within the housing after insertion. The retainer remains on the housing at all times during insertion and removal of the male conduits. Also, the present invention provides the art with a female housing having a pair of slots defining ramped surfaces in the housing wall. The ramped surfaces enable the hair pin style retainer to move or slide along the ramped surfaces, within the slots, to enable insertion and removal of the male conduit.
From the following detailed description and preferred embodiment of the present invention, other objects and advantages of the present invention will become apparent to those skilled in the art.

Conduit quick connector assembly having a ramped housing with a hair pin retainer


The invention relates to a diffractive optical element which comprises a first substrate and a second substrate, between which a liquid crystal layer is provided. The diffractive optical element also has strip-shaped electrodes on the first substrate and strip-shaped electrodes on the second substrate. The electrodes on the first substrate are arranged at an angle of greater than 50° relative to the electrodes on the second substrate. Furthermore, the electrodes on the first substrate and the electrodes on the second substrate are controllable in such a way that a defined out-of-plane field can be produced in a respective overlapping area of the electrodes on the first substrate with the electrodes on the second substrate. The diffractive optical element can be used in a display device for displaying preferably three-dimensional scenes.

The invention relates to a diffractive optical element for steering of light or for direction of light in a defined direction or for adaptation or adjustment of a field of view.
The invention also further relates to a display device for display of two-dimensional and/or three-dimensional objects or scenes having such a diffractive optical element.
There is a multitude of applications in which optical elements can be used for steering of light or for establishment of a field of view, for example in optical data transfer or in display devices or displays for representation of information in two-dimensional and/or three-dimensional form. In such display devices, especially in holographic display devices, diffractive optical elements are frequently used for controlled deflection of light. For example, a diffractive optical element may be used for observer tracking in a display device, in order to track light for generation of a preferably three-dimensional scene in the event of a change in position of an observer relative to the display device to a new position of the observer, or to direct it to the observer's new position.
In the case of holographic display devices having at least one virtual observer region that can also be referred to as virtual observer window, the scene or object generated in holographic form can be observed only when an eye of an observer of the scene is at the position of the virtual observer region, such that the observer can observe the scene represented on viewing through this virtual observer region. For this purpose, the observer must assume a fixed position relative to the display device. If, however, the observer moves to another position with respect to the display device, for the observer to be able to continue to observe the scene or information presented, the virtual observer region must be moved to the new position of the observer's eye.
A known option of observer tracking in display devices is the tracking or defined direction of the light by appropriate encoding of phase responses in addition to the encoding of a hologram in a spatial light modulation device provided for modulation of incident light and for generation of the reconstructed scene.
A further option of observer tracking involves the use of diffractive optical elements or devices, for example diffraction devices. Such diffractive optical elements or devices are designed to be controllable.
U.S. Pat. No. 8,860,896 B2, for example, discloses a phase modulator comprising a first substrate and a second substrate, an electrode arrangement and a liquid-crystal layer with liquid-crystal molecules. The first substrate is disposed opposite the second substrate, with the liquid-crystal layer disposed between the two substrates. The electrode arrangement has strip-shaped electrodes on only one substrate, while the other substrate has a planar electrode or no electrode. Such a phase modulator can also be used to achieve a variable diffraction grating by means of control of the in-plane electrodes on the one substrate. An in-plane field is generated here between each two strip-shaped electrodes on the same substrate. This makes it possible to create variable orientations of the liquid-crystal molecules of the liquid-crystal layer, such that variable grating periods can be generated. By writing a diffraction grating into the phase modulator with a particular grating period, it is thus possible to deflect light.
A phase deflector that uses an out-of-plane field between in each case a strip-shaped electrode on a first substrate and an electrode on a second substrate which is planar or likewise strip-shaped and runs parallel to the electrode of the first substrate is described in US 2012/0206667 A1. Here too, by writing a diffraction grating with a defined grating period into the phase deflector, deflection of light is achieved in a direction perpendicular to the alignment of the electrode lines. By variation in the grating period written, it is possible to alter the angle of light deflection.
US 2014/0055692 A1 describes the use of a diffraction device for observer tracking in a holographic display device. This diffraction device likewise comprises strip-shaped electrodes on at least one substrate. The deflection of light in a direction perpendicular to the alignment of the electrode lines is effected here too by writing a diffraction grating having a defined grating period into the diffraction device. The grating period may be varied here in order to alter the angle of light deflection. Various configurations of the diffraction device are described. In some configurations, an out-of-plane electrical field between in each case a strip-shaped electrode on a first substrate and an electrode on a second substrate which is planar or likewise strip-shaped and runs parallel to the electrode of the first substrate is used here.
In all the prior art elements or devices detailed here, in-plane fields or out-of-plane fields are used in combination with a respective liquid-crystal (LC) mode for which diffraction gratings can be adjusted with the aid of the respective fields.
Diffraction devices with generated in-plane fields may be based, for example, on an HAN (hybrid aligned nematic) mode or a CIPR (continuous in plane rotation) mode, as described in U.S. Pat. No. 8,860,896 B2.
Diffraction devices with generated out-of-plane fields may be based, for example, on an ECB (electrically controlled birefringence) mode, and they may also be based on liquid-crystal modes that use smectic liquid crystals, in which case the liquid-crystal molecules can perform in-plane rotation in the out-of-plane field.
In a holographic display device or a display, in general, observer tracking requires deflection of light both in horizontal and in vertical direction.
The prior art, for example as described in US 2014/0055692 A1, discloses using an arrangement composed of at least two diffraction devices for the purpose. The electrodes of a first diffraction device and the electrodes of a second diffraction device here are in an arrangement rotated essentially by 90 degrees relative to one another, or the two diffraction devices are provided with rotation relative to one another. For example, the first diffraction device in that case deflects the incident light in horizontal direction, with the second diffraction device deflecting the light in vertical direction. In order to perform observer tracking in depthwise direction (z direction) as well, at least two diffraction devices are used. A cylindrical lens function is written into each of the at least two diffraction devices, with the at least two crossed cylindrical lens functions approximating to a spherical lens. The diffraction devices may, for example, also be rotated or tilted by 45 degrees relative to a horizontal or horizontal line, such that the first diffraction device deflects the light by 45 degrees and the second diffraction device deflects light by 135 degrees.
Typically, a holographic display device comprises at least one light modulation device and at least two diffraction devices for deflection of light and hence for observer tracking.
Frequently, the light modulation device as well as the diffraction devices has ITO (indium tin oxide) electrodes on at least one substrate, the refractive index of which is distinctly different from the refractive index of the surrounding substrate, for example glass, and from the refractive index of the liquid-crystal layer. Reflection of light at the boundary surfaces between the ITO electrode and the substrate can, for example, impair the contrast of the scene represented. By absorption of light in the ITO electrodes, the brightness of the scene represented can be lowered additionally. In addition, these effects can be enhanced by an increasing number of ITO electrode layers in a display device.
The prior art includes further documents, for example US 2013/0222384 A1, which disclose alternative possible uses of diffraction devices. This includes use of diffraction devices in order, for example, to enable a large viewing angle or a large field of view in a head-mounted display (HMD). For such applications of diffraction devices too, pairs of one diffraction device for horizontal light deflection and one diffraction device for vertical light deflection or for horizontal and vertical focusing of light are typically used. For use of at least one diffraction device in a head-mounted display, it would especially also be advantageous to use at least one reflective diffraction device having, for example, reflective metal electrodes on a substrate or else transparent electrodes combined with a reflective layer disposed in some other way, either in the direction of passage of light through the diffraction device, upstream or downstream of the electrodes, for example either a metal layer or a dielectric mirror layer.
Frequently, however, pairs of diffraction devices are required for horizontal and vertical deflection of light at roughly the same location or position in a holographic display device. However, the use of reflective diffraction devices would require a minimum distance between the diffraction device for vertical deflection and/or vertical focusing of the light and the diffraction device for horizontal deflection and/or horizontal focusing of the light for modulated light to run successively and correctly through both diffraction devices in the light path.

Diffractive optical element and display device