A system and method for calculating an optimum transmission power level in an ad-hoc network communication path having a maximum number of transmission hops. The system and method calculates an optimum transmission power level for transmission routes having a maximum number of hops between nodes and transmits the communication using the calculated power level such that a transmission path is achieved that results in a maximum pipeline delay during transmission that does not exceed allowable levels for the service class provided.

1. Field of the Invention
The present invention relates to a system and method for calculating an optimum allowable transmission power level in an ad-hoc network communication path. More particularly, the present invention relates to a system and method for calculating an optimum transmission power level for transmission routes having a variable number of hops between nodes resulting in a maximum pipeline delay during transmission that does not exceed allowable levels for the service class provided.
2. Description of the Related Art
Ad-hoc networks have become a rapidly growing application in wireless mobile communications. An ad-hoc network is comprised of a number of mobile devices which are capable of direct and indirect communication with one another, such that each mobile device may be used as a router for data packet transmissions from other mobile devices. Transmitted data packets "hop" from mobile device to mobile device, creating a transmission path, until reaching a final destination. However, transmission paths between mobile devices are often subject to change as devices move, therefore ad-hoc network communication must be able to adapt and establish paths with optimum performance.
Typically, moving devices within an ad-hoc network result in variations in transmission path distance and associated transmission power levels. Although intelligent access points (IAPs) and stationary routers may theoretically include unlimited power supplies to provide transmission power, mobile devices are typically powered from rechargeable batteries. Therefore, a significant operation parameter in ad-hoc networks is the selection of transmission paths between devices requiring the lowest power consumption levels. Given no other factors, a transmission path comprised of short hops between multiple, closely spaced mobile devices will typically require less transmission power than a path comprised of fewer hops between widely spaced devices. Therefore a path requiring less transmission power is often possible where a large number of dispersed mobile devices within an ad-hoc network exist. Longer, direct transmission paths with fewer hops, as in the case occurring when an ad-hoc network has fewer dispersed mobile devices, will typically require greater transmission power levels. Therefore, a transmission path comprised of short hops between close mobile devices when possible, is the preferred communication route to conserve the limited power resources of mobile devices. However, a second factor beyond transmission path power consumption must be considered in ad-hoc communications networks.
As data packets are transmitted between multiple mobile devices, a cumulative transmission delay is created, which is not present in more direct transmission routes. Delays resulting from excessive hopping may be unsuitable for many service classes. For example, the "pipeline delays" resulting from excessive hopping is unsuitable for telephone communication, however certain data transfers may tolerate these larger delays. When the maximum accepted pipeline delay is small, the number of hops along the route between correspondents or between one correspondent and its IAP must be smaller than the number of hops along routes supporting unidirectional data transfer. As discussed above, transmission routes having a large number of hops require less transmission power, while routes having fewer hops, such as routes required for interactive voice data, use higher transmission powers. The resulting selected route in each case therefore, must satisfy pipeline delay requirements as well as address power consumption concerns for battery powered mobile devices.
Presently, routing schemes have included a number of methods. As described in U.S. Pat. No. 5,987,011 to Toh, which is incorporated herein by reference, conventional routing schemes are typically based on either broadcast or point-to-point routing. As discussed in Toh, numerous routing schemes have been implemented including cluster-based routing, destination sequence distance-vector routing and dynamic source routing. Each technique uses some combination of point-to-point and broadcast routing using the connection-oriented packet forwarding approach. Although each routing scheme provides a transmission path, no concern is given to the pipeline delay restrictions for differing service classes or the restricted power supplies of mobile devices. Excessive pipeline delays are often unacceptable for many service classes, however, transmission paths with lower delays typically require greater transmission power levels.
Accordingly, a need exists for a system and method in which maximum pipeline delays are determined for service classes in an ad-hoc network, and an optimum transmission power level calculated for a selected transmission path satisfying these delay requirements.

System and method for controlling pipeline delays by adjusting the power levels at which nodes in an ad-hoc network transmit data packets


L-valine is produced by culturing a microorganism belonging to the genus Escherichia with the capability of producing L-valine or L-leucine wherein it requires lipoic acid for growth, a microorganism belonging to the genus Escherichia with the capability of producing L-valine or L-leucine wherein it is deficient in H.sup.+ -ATPase activity, a microorganism belonging to the genus Escherichia with the capability of producing L-valine or L-leucine wherein it requires lipoic acid for growth and is deficient in H.sup.+ -ATPase activity, in the liquid medium to allow the L-valine to be produced and accumulated in a culture medium, and collecting it.

In the past, L-valine and L-leucine have been produced by a method of fermentation primarily using a microorganism belonging to the genus Brevibacterium, Corynebacterium or Serratia or a mutant thereof which produces L-valine or L-leucine (Amino acid fermentation, JAPAN SCIENTIFIC SOCIETY'S PRESS, pp.397-422, 1986). Although the conventional methods have considerably enhanced the productivity of these amino acids, the development of a more efficient, cost-effective technique is required in order to meet increasing demand for L-valine and L-leucine in the future.
On the other hand, a microorganism belonging to the genus Escherichia is potentially utilized as a potent L-valine or L-leucine-producing microorganism due to its rapid growth rate, progress in genetic analysis and plentiful genetic materials. However, there are few reports documenting the production of these amino acids with from Escherichia microorganisms, and as for L-branched chain amino acids, only a few reports deal with the production of L-isoleucine (Japanese Patent Application Laid-Open No. 5-304969(1993) and Japanese Patent Application Laid-Open No. 5-130882(1993).

Methods for producing L-valine and L-leucine


A fluid valve and bin aerator for discharging fluid into a chamber while preventing backflow of fluid through the fluid valve with the fluid valve including a resilient member having a set of annular sealing lips located in concentric alignment and at an angle to a sealing surface to provide lips that will cantilever away from the sealing surface and unseal if the pressure on the interior of the fluid valve is greater than on the exterior of the valve to allow fluid to be discharged from the valve, and will cantilever against the sealing surface if the pressure on the exterior of the valve is greater than the pressure on the inside of the valve to seal the fluid valve and inhibit backflow through the fluid valve.

The concept of bin aerators is old in the art as evidence by my U.S. Pat. No. 3,952,956, which discloses a bin aerator that has a deformable rubber housing for discharging air parallel to the walls of the bin. Generally, the bin aerators are periodically pulsed with a high pressure gas to discharge the gas into the pneumatic conveying system. At other times, gas may be continually discharged for an extended period of time. The resultant flow of gas around the deformable rubber housing dislodges the material adjacent the bin aerator. When the gas flow terminates, the deformable rubber housing collapses inwardly to seal off the gas passage and prevent backflow of material into the bin aerator.
In the present invention, an improved bin aerator incorporates a one-piece resilient domed member that has a sealing flap and multiple cantileverly held sealing lips that flex radially outward to allow gas to escape therefrom, but seal and seat themselves against a sealing surface when the gas pressure on the outside of the bin aerator is greater than the pressure on the inside of the bin aerator, thus preventing the backflow of gasses. The bin aerator is particularly suitable for use with abrasive materials, as the gas discharged from the bin aerator follows the angled sealing surface and is directed away from the wall of a pneumatic conveying device to thereby reduce abrasion caused by entrained particles. Also, the sealing lips are maintained in sufficiently strong pressure contact with a sealing surface so that as the scaling lips wear during use, the resilient member can still maintain an effective seal against the sealing surface. In addition, the bin aerator includes a housing that can be quickly mounted into a bin extension.


An image forming apparatus may include a main body having a developing apparatus, a driving source configured to generate power in the main body, a driven unit configured to receive the power from the driving source to be operated, a supply cassette configured to be detachable from the main body and in which printing media are stacked, and an opening/closing unit configured to receive power from the driving source configured to drive the driven unit to move the supply cassette back and forth. Accordingly, the supply cassette can be automatically opened and closed to provide user convenience.

1. Field
Embodiments relate to a printing medium supplying apparatus and an image forming apparatus having the same, and more particularly, to a printing medium supplying apparatus having an automatic opening/closing structure, and an image forming apparatus having the same.
2. Description of the Related Art
In general, an image forming apparatus is an apparatus for forming an image on a printing medium according to an input signal, and may be a printer, a copier, a fax machine, a multi-functional printer implemented by integrating functions thereof, and so on.
Such an image forming apparatus has a printing medium supplying apparatus configured to supply a printing medium. Conventionally, the printing medium supplying apparatus picks up stacked printing media one by one to supply the printing medium to a main body of an image forming apparatus.
The printing medium supplying apparatus includes a supply cassette in which a plurality of printing media is to be supplied to the image forming unit, and a knock-up plate installed at the supply cassette to be elevated.
However, when the supply cassette is manually opened and closed, the supply cassette may be broken or the stacked printing media may become disordered when an impact is large.

Printing medium supplying apparatus and image forming apparatus having the same


An optical assembly may include a waveguide and a Bragg grating configured to couple light into or out of the waveguide. The Bragg grating may include a plurality of layer pairs, wherein at least one layer pair comprises a first material having a first refractive index and a second layer having a second refractive index, and wherein properties of the Bragg grating are selected so that the Bragg grating exhibits a substantially similar diffractive efficiency and diffraction angle for light of at least two colors.

Artificial reality systems have applications in many fields such as computer gaming, health and safety, industry, and education. As a few examples, artificial reality systems are being incorporated into mobile devices, gaming consoles, personal computers, movie theaters, and theme parks. In general, artificial reality is a form of reality that has been adjusted in some manner before presentation to a user, which may include, e.g., a virtual reality, an augmented reality, a mixed reality, a hybrid reality, or some combination and/or derivatives thereof.
Artificial reality systems often use a head mounted display (HMD) to present images to a user. For the user to comfortably view the images displayed by the HMD, an optical system is used to shape light and direct it to the user's eye. Because the user wears the HMD on their head, size and weight are important considerations. Additionally, reducing or eliminating image artifacts or distortion is important for enabling a comfortable viewing experience.

Artificial reality system having Bragg grating


The number of compensation capacitors of an opamp may be reduced by connecting the compensation/decoupling capacitor element or elements between the load node and the bias node of the operational amplifier, rather than providing separate capacitive elements from each load node to ground (the reference voltage). This allows one to both reduce the overall area occupancy of the operational amplifier, and/or to improve the settling characteristics of its common-mode and differential output signal. The opamp may be part of a multi-stage amplifier or an analog-to-digital converter (ADC) (e.g., a pipelined ADC), which may form part of a multi-stage wireless communications base station receiver.

The present invention in some aspects relates to gain-boosted operational amplifiers (opamps). In other aspects, the invention relates to opamps for pipelined analog-to-digital converters (ADCs).
Operational amplifiers are employed in many different types of devices. For example, wireless communications systems have base station receiver chains that employ analog-to-digital converters (ADCs), and each ADC may employ opamps. The pipelined ADC architecture is employed to build high speed and high resolution ADCs, each having an analog core which employs high gain, high frequency opamps.
Pipelined ADCs have become a de facto standard in base station receiver chains for wireless communication systems. The pipelined ADC has a fast architecture, and is believed to provide a fair compromise among resolution, power consumption, and conversion speed.
In certain contexts, such as in base station receiver chains implemented in a miniaturized integrated circuit (IC) (such as an SOC (system on a chip)), there is a desire to scale down the voltage supply of the pipelined ADC.
Pipelined ADCs and their components, particularly the opamps they employ, continue to evolve. Efforts are underway to reduce the voltage supply level required for the pipelined ADC to levels at 3.3V and below, to allow further miniaturization of the integrated circuit (IC) and to lead to inclusion of such devices in an SOC (system on a chip). Meanwhile, the gain levels for these pipelined ADCs are beyond 80 dB for ADC resolutions of 12 or more bits per word, while the intrinsic gain for a given transistor may be well below 30 dB. Add to these constraints the continued necessity that these circuits operate well at high speeds.
Various pipelined ADCs have been designed to attain higher gains and speeds. To this end, various improved opamp structures are being introduced, including one-stage telescopic amplifiers, opamps with a single stage preceded by low-gain preamplifiers, or two-stage opamp architectures. In each of these opamp structures, some form of cascoding is adopted on the main gain stage, to make up for a reduced output impedance of the transistors (i.e. reduced Early voltage). This approach also takes advantage of the better transconductance (gm) of short-channel transistors.
The following references describe examples of opamp structures generally taking this approach.    [1] A. Loloee, A. Zanchi, H. Jin, S. Shehata, and E. Bartolome, "A 12 b 80 MSps Pipelined ADC Core With 190 mW Consumption from 3V in 0.18 μm Digital CMOS", in Proceedings of the IEEE European Solid-State Circuits Conference (ESSCIRC 2002), Florence (Italy), Sep. 24–26, 2002, pp. 467–470.    [2] B. M. Min, P. Kim, D. Boisvert, and A. Aude, "A 69 mW 10 b 80 MS/s Pipelined CMOS ADC ", IEEE ISSCC Digest of Technical Papers, San Francisco, Calif., February 2003, pp. 324–325.    [3] A. R. Bugeja and S. U. Kwak, "Design of a 14 b 100 MS/s Switched-capacitor Pipelined ADC in RFSiGe BiCMOS", in Proceedings of the ISCAS 2001, Sydney, Australia, May 2001, pp. 428–431.    [4] L. Singer, S. Ho, M. Timko, and D. Kelly, "A 12 bit 65 Msample/s CMOS ADC with 82 dB SFDR at 120 MHz", in ISSCC Digest of Technical Papers, San Francisco, Calif., February 2000, pp. 38–39.    [5] A. Zanchi, F. Tsay, and I. Papantonopoulos, "Impact of Capacitor Dielectric Relaxation on a 14-bit, 70-MSps Pipeline ADC in 3-V BiCMOS", in press for IEEE Journal of Solid-State Circuits, December 2003.    [6] D. Kelly, W. Yang, I. Mehr, M. Sayuk, and L. Singer, "A 3V 340 mW 14 b 75 MSps CMOS ADC with 85 dB SFDR at Nyquist", in ISSCC Digest of Technical Papers, San Francisco, Calif., February 2001, pp. 134–135.
Existing opamp structures, such as those identified above, may not sufficiently boost their gain, with a requisite level of performance. Accordingly, other techniques may be employed to facilitate gain-boosting, including using an auxiliary amplifier to reinforce the output impedance of the principal transconductance amplifier. This is discussed, for example, by Bult et al., "A Fast-settling CMOS Opamp for SC Circuits With 90-dB DC Gain", IEEE Journal of Solid-State Circuits, Vol. 25, December 1990, pp. 1379–1384.
Popular circuits which provide a gain-boosting function include a single-ended common-source stage as disclosed by Bugeja et al. (see citation above), or a form of differential folded-cascode servo-amp, as disclosed by Loloee et al. (citation above), or Min et al. (citation above).
These solutions generally share a common problem of pole-zero doublet compression. Apfel et al., "A Fast-settling Monolithic Operational Amplifier Using Doublet Compression Techniques", IEEE Journal of Solid-State Circuits, Vol. 9, No. 6, December 1974, pp. 332–340.
Doublet compression can be relieved by placing a capacitor (otherwise referred to as a compensation capacitor) within the loop of the booster to limit its bandwidth of response. This prevents the doublet from approaching the second pole of the main opamp, and moves the pole and zero closer to each other in absolute terms. The result is that the opamp AC response has a smoother phase profile.
Opamp structures will typically also "ballast" the internal voltage reference nodes generated by the bias network of the opamp (often a series of diodes) with a localized capacitor. This is done to filter out voltage spikes propagating from the power supply, and to limit the high frequency noise as much as possible.
FIG. 1 is a schematic of a background amplification circuit, improved upon by employing circuits later illustrated in FIGS. 2 and 3. The illustrated circuit comprises a one stage BiCMOS opamp. The illustrated opamp 10 comprises bias circuitry 12 and an output stage 14. The illustrated output stage 14 comprises transductance elements 16, corresponding cascode elements 18, current source elements (active load) 20, corresponding cascode elements of the load 26, and gain boosters 24.
Current source elements 20 are connected to corresponding current source cascode elements 26, which are in turn connected to transconductance elements 16 via respective corresponding cascode elements 18. Tail elements 22 are provided between transconductance elements 16 and a reference voltage node AVSS, which is zero volts in the illustrated embodiment. Current source elements 20 are coupled to a DC power supply AVDD, which in the illustrated embodiment is 3.3V.
In the illustrated amplification circuit 10, bias circuitry 12 comprises a bias node 13 connected to the base of each of corresponding cascode elements 18, which correspond to transconductance elements 16. Cascode elements 18 and their corresponding transductance elements 16 form part of output stage 14. Bias circuitry 12 further comprises a current source 28 and a set of interconnected diode elements. In the simplified circuit illustrated, those diode elements are n type and p type transistor elements, specifically comprising PMOS field effect transistors (FETs) T1 and T2, an npn bipolar junction transistor (BJT) T11, and NMOS field effect transistor (FETs) T14, T17, and T18.
Transconductance elements 16 comprise npn BJTs T15 and T16. Tail elements 22 comprise NMOS FETs T19 and T20. Corresponding cascode elements 18 comprise npn BJTs T12 and T13. Current source elements 20 comprise PMOS FETs T3 and T4. Corresponding source cascode elements 26 comprise PMOS FETs T5 and T8.
The illustrated amplification circuit 10 serves as a differential amplifier with differential inputs, the amplification of which is represented across the differential outputs. In the illustrated embodiment, the differential inputs comprise INp (Vin-p) and INn (Vin-n), which comprise the respective bases of transconductance elements 16. The illustrated circuit further comprises outputs OUTn (Vout-n) and OUTp (Vout-p), located at which points between the drains of corresponding current source cascode elements 26 and the collectors of cascode elements 18.
The illustrated circuit 10 further comprises gain boosters 24. Each booster 24 is connected between a sense node 29 at its input, to read the intermediate voltage between load 20 and respective cascode element 26; and a driven node 25 at its output, to control the node's voltage level forming a feedback loop around the cascode element 26, which increases its output impedance. The boosters 24 are supplied by the same voltages AVDD and AVSS as the whole opamp, whereby AVDD is 3.3V and AVSS is 0V in the illustrated embodiment. Boosters 24 are respectively connected to outputs OUTn and OUTp via the corresponding current source cascode elements 26. Gain boosters 24 serve to increase the impedance across the output of the circuit, thereby increasing the amplification of the voltage signal between the input terminals and the output terminals. Specifically, the gain is equal to [(Vout-p)−(Vout-n)]/[(Vin-p−Vin-n)]. The illustrated circuit 10 comprises a set of circuit elements that form a P-block, meaning that the elements contained within that portion of output stage 14 are generally P type elements (PMOS FETs, pnp BJTs). Another set of elements form an N-block meaning that those elements are generally N type elements (NMOS FETs, npn BJTs).
In the illustrated circuit, the active loads implemented in the P-block comprise respective gain booster portions 24. In the circuit of FIG. 1, gain booster portions 24 comprise two single-ended servo-opamps.
FIG. 3 presents AC response plots for the operational amplifier shown in FIG. 1. Specifically, the smoothness of the phase plot of the amplifier (and consequently its phase margin) can be improved by increasing the capacitances value of the compensation capacitor 30 within the one stage operational amplifier shown in FIG. 1. This is confirmed by the waveforms shown in FIG. 3, which illustrates the gain AC response and the phase AC response of the noted circuit, for different compensation capacitor values ranging from as high as 7 picofarads to as low as 1 attofarads (lowest curve in the phase plot). The higher compensation capacitor value of 7 picofarads results in the better waveform AC responses, particularly a better phase response. It is beneficial to increase the amount of capacitance of the compensation capacitor. Specifically, by increasing the amount of capacitance, the long-term voltage ringing at the output of the differential amplifier can be zeroed out. Analogously, increasing the amount of capacitance of the capacitor decoupling the bias node 13 toward a steady voltage (AVSS in the illustrated embodiment) enhances the common-mode stability of the amplifier 10.

Gain-boosted opamp with capacitor bridge connection


A lighting apparatus is disposed near an upper end edge of a license plate on a rear side of a vehicle. The lighting apparatus includes a license plate lamp which illuminates the license plate with visible light, and an infrared irradiation lamp which irradiates a region behind the vehicle with infrared light. The license plate lamp includes a first light emitting device which emits the visible light and is supported on a rear surface of a first support plate. The infrared irradiation lamp includes a second light emitting device which emits the infrared light and is supported on a lower surface of a second support plate. A lower end of the first support plate is coupled to a rear end of the second support plate. When seen from behind the vehicle, the license plate lamp is disposed directly above the infrared irradiation lamp.

1. Field of the Invention
The present invention relates to a vehicle lighting apparatus, which is disposed near an upper end edge of a license plate, having a license plate lamp and an infrared irradiation lamp.
2. Related Art
A related art license plate lamp, which is disposed near an upper end edge of the license plate, illuminates a license plate on a rear side of a vehicle with visible light.
A related art lane mark irradiating lamp, which is an infrared irradiation lamp, irradiates an obliquely rear region of a road surface behind the vehicle with infrared light. While being irradiated with the infrared light, an image of the road surface behind the vehicle is captured by an infrared camera and is displayed on a monitor. Thus, lane marks (e.g., right and left white lines extending along the lane on which the vehicle is running) can be recognized. This may be used for an automatic driving control of the vehicle.
Generally, these license plate lamp and lane mark irradiating lamp are separately provided in a rear part of the vehicle.
A related art lighting apparatus includes a license plate lamp and a back monitoring lamp, which are both arranged near an upper end edge of a license plate (see, e.g., JP 2007-145048 A). This back monitoring lamp is also an infrared irradiation lamp, but is different from the lane mark irradiating lamp in that, for example, it irradiates a wider range of a road surface behind the vehicle with infrared light.
If the back monitoring lamp is replaced with a lane mark irradiating lamp in the related art lighting apparatus described above, the license plate lamp and the lane mark irradiating lamp will be disposed near the upper end edge of the license plate so as to be configured as a single lighting apparatus.
However, if the back monitoring lamp is simply replaced with a lane mark irradiating lamp in the related art lighting apparatus described above, following problems will occur.
The back monitoring lamp is turned on when capturing an image of the road surface behind the vehicle with an infrared camera during a backing movement of the vehicle. In contrast, the lane mark irradiating lamp is continuously turned on during the night time, for example, to execute an automatic driving control. The lane mark irradiating lamp uses near-infrared light. Thus, irradiation light of the lane mark irradiating lamp partially contains red light. Accordingly, when the lane mark irradiating lamp is turned on during the night time and is seen from behind the vehicle, the lane mark irradiating lamp looks reddish. This gives a strange feeling to drivers of vehicles following behind.
During the night time, the license plate lamp is also continuously turned on. Therefore, if the lane mark irradiating lamp is disposed adjacently below the license plate lamp, the light from the license plate lamp can effectively suppress the lane mark irradiating lamp from looking reddish.
However, in the related art lighting apparatus described above, the back monitoring lamp is configured such that a lens is disposed to control the infrared light emitting from a backwardly facing light emitting device. Thus, if the license plate lamp is disposed adjacently above the back monitoring lamp, the light from the license plate lamp will partially be blocked or becomes uncontrollable due to the light emitting device and the lens of the back monitoring lamp. Therefore, in the related art lighting apparatus described above, the license plate lamp and the back monitoring lamp are spaced from each other in a widthwise direction of the vehicle.
Accordingly, if the back monitoring lamp is simply replaced with a lane mark irradiating lamp in the related art lighting apparatus, there will a problem that the light from the license plate lamp cannot be utilized to suppress the lane mark irradiating lamp from looking reddish.


A liquid crystal display device in which a pair of substrates having electrodes face each other, and liquid crystal is sealed between the substrates. The liquid crystal display device includes a insulating layer that varies electric field orientations in a pixel region when a voltage is applied between the pair of substrates.

In recent years, liquid crystal display devices have been widely used because of their advantageous features, such as thinness, lightness, low driving voltage, and low power consumption. Particularly, active-matrix liquid crystal display devices having an active element for each pixel, such as TFT-LCDs (Thin Film Transistor Liquid Crystal Displays) have been becoming comparable with CRTs in terms of display quality.
However, the use of LCDs has been limited due to a narrow viewing angle. In order to eliminate this problem, various techniques have been suggested. Among those techniques, there are many techniques in which electrodes are patterned so as to control the inclinations of liquid molecules in various directions by changing the field distribution in cells. However, the electrode patterning techniques cause problems described later herein. The present invention can be applied to all of the electrode patterning techniques, and easily solve those problems.
First, LCDs that are generally used for display devices will be described. At present, the most commonly used LCDS are TN (Twisted Nematic) LCDs of normally white mode. FIG. 1A shows the panel structure of such a TN-LCD. In FIG. 1A, TN liquid crystal 12 is sandwiched by glass substrates having alignment layers 10 and 11 having orientated directions deviated by 90 degrees from each other. Accordingly, the liquid crystal in contact with the alignment layers 10 and 11 are aligned in the orientated directions of the alignment layers, and the other liquid crystal molecules are orientated along the aligned liquid crystal molecules. As a result, the molecules are twisted through 90 degrees. Further, the liquid crystal and the alignment layers 10 and 11 are sandwiched by two polarizing plates 13 and 14 that are situated in parallel with the orientated directions of the upper and lower portions of the liquid crystal, respectively. When light impinges on the panel having the above structure, the light passing through the polarizing plate 13 turns into linearly polarized light and enters the liquid crystal 12. Along with the liquid crystal 12 twisted through 90 degrees, the light is also twisted through 90 degrees while passing through the lower polarizing plate 14. Here, the display is in a bright state.
As shown in FIG. 1B a voltage is applied between the alignment layers 10 and 11, thereby straightening the liquid crystal molecules and eliminating the twist. However, on the surfaces of the alignment layers 10 and 11, the liquid crystal molecules remain along the alignment layers 10 and 11 due to the strong orientation force. In this situation, the liquid crystal 12 is almost homeotropic with the linearly polarized light, and no rotation of the polarizing direction occurs. Here, the display is in a dark state. When the voltage is zero, the display returns to a bright state due to the orientation force y on the alignment layers.
Next, an IPS (In-Plane Switching) method that realizes a wider viewing angle will be described. For instance, Japanese Patent No. 53-48542 and Japanese Patent No. 1-120528 disclose methods in which an electric field in parallel with the substrates is generated in liquid crystal layers. As shown in FIG. 2A, according to this method, a pair of striped electrodes 21 and 22 are formed on a substrate 20 on one side, and the liquid crystal molecules located between the slit-like electrodes 21 and 22 are driven by a lateral electric field. The liquid crystal 23 is made of a material having positive dielectric anisotropy. When no electric field is applied, the liquid crystal molecules are homogeneously aligned in parallel with the longitudinal direction of the striped electrodes 21 and 22, as shown in the plan view of FIG. 2B (i.e., the liquid crystal molecules are homogeneously orientated at an angle of approximately 15 degrees, so that the direction of the liquid crystal molecules becomes uniform when a voltage is applied).
When a voltage is applied between the striped electrodes 21 and 22, the directors of the liquid crystal molecules having dielectric anisotropy are changed, as shown in FIGS. 3A and 3B. In such a liquid crystal display device, polarizing plates 25 and 26 are arranged on and under substrates 20 and 24, with the polarizing axes or the absorbing axes crossing perpendicularly to each other. One of the polarizing axes is located in parallel director direction, so that a black display can be realized when no voltage is applied and a white display can be realized when a voltage is applied.
There have been dramatic improvements in the TN-type TFT-LCD production techniques, and, in recent years, the TN-type TFT-LCD production techniques excel CRTs in contrast ratio and color reproducibility. However, the LCDs have a narrow viewing angle. Particularly, a TN-type has only a very narrow viewing angle in the vertical direction. Viewed front sonic other direction, the brightness of the black state increases, making the image whitish. Viewed from the other direction, the display becomes dark, and gray-scale inversion occurs.
When a voltage is applied to TN liquid crystal cells, the liquid crystal molecules are inclined in some degree. At this point, the birefringence of the liquid crystal layer makes the cells have a gray scale transmittance. However, this is the case only when the liquid crystal panel is seen from the front, and the liquid crystal panel looks different when it is seen from an oblique angle. In FIG. 4, the appearance seen from the left is different from the appearance seen from the right. For instance, the liquid crystal has little birefringence effect on the light directed from the lower left to the upper right in FIG. 4. Accordingly, when seen from the right, the panel looks black, not gray. On the other hand, with the light passing from the lower right to the upper left, the birefringence effect becomes larger. As a result, the display looks even whitish and closer to white.
To solve this problem, it is effective to employ the technique of multidomain. According to this technique, a plurality of inclined directions of the liquid crystal molecules exist in one pixel. Because of this, the left half of the pixel in FIG. 5 exhibits a large birefringence for the light passing from the lower left to the upper right (white display), and the right half of the pixel exhibits little birefringence (white display). In such a condition, the display appears to be a gray scale image to a human eye, as long as the division size is small enough. When seen from the left, the display appears to be gray for the same reason. From seen from the front, the display of course appears to be gray because the inclined angles of the liquid crystal molecules are uniform on both left and right sides. Thus, uniform gray scale image can be obtained throughout a wider viewing angle range.
To achieve a multidomain structure, a mask rubbing process shown in FIG. 6 can be used. When an alignment layer is rubbed with a rubbing roller made of nylon or polyester, the liquid crystal molecules have tendency to be orientated in the rubbing direction. Taking advantage of this tendency, alignment layers 32 and 33 of substrates 30 and 31 are subjected to rubbing in the right direction by rubbing rollers 34 and 35, as shown in FIG. 6A. Next, a half of each pixel is subjected to masking with resists 36 and 37, as shown in FIG. 6B. The alignment layers 32 and 33 are then subjected to rubbing in the left direction, as shown in FIG. 6C. The resists 36 and 37 are then removed, and the substrates 30 and 31 are attached to each other, with liquid crystals inside, thereby completing a liquid crystal cell having the left and right orientation directions.
With the mask rubbing method, however, there exist many problems. These problems include the low productivity due to the complicated process, the limitation on the number of divisions (at least four divisions are necessary to satisfy all the conditions with respect to contrast, color, and gray scale, but the maximum number of divisions is 2 because of the complicated process), and poor controllability in the rubbing process due to the masking process. For these reasons, it has been very difficult to mass-produce the multidomain panels by the mask rubbing process.
Other techniques to solve the above problems and to achieve a wider viewing angle include a method in which an electric field distortion is caused in a cell so as to control the alignments. However, there are other problems in this case, such as the difficulty in patterning electrodes, poor yield, and higher costs due to a larger number of processes. Furthermore, if a minutely striped electrode is formed from an ITO (indium tin oxide) layer, a voltage drop is caused at the end portion of the electrode, resulting in display unevenness.
In the IPS method, the liquid crystal are switched in the horizontal direction. As mentioned before, when the liquid crystal molecules are aligned with an inclined angle to the substrates, the birefringence varies with the viewing angle direction. The switching is carried out in the horizontal direction so as to steady the birefringence and obtain excellent viewing angle characteristics. However, this method also causes several problems. First of all, the response is very slow, because the switching is carried out with an electrode gap of about 10 μm in the IPS method, compared with the switching with an electrode gap of about 5 μm in the conventional TN method. The response time can be shortened by narrowing the electrode gap, but each two adjacent electrodes needs to have a different electrical potential to apply an electrical field. Otherwise, short-circuiting will occur between the adjacent electrodes, resulting in a display with defects. To avoid such a problem, each two adjacent electrodes are formed on two different layers, but this simply increases the number of manufacturing processes.
Also, since it is difficult to form minutely striped electrode with ITO, striped metal electrodes are employed instead. However, this causes a loss in the aperture ratio. If the pitch of the striped electrode is narrowed to increase the response speed, the proportion of the electrode to the total area becomes large, resulting in lower transmittance. (In reality, the transmittance of the IPS method is only two thirds of the transmittance of the TN method. If the electrode pitch is halved and the density of the striped electrode is doubled, the transmittance becomes only one third of the transmittance of the TN method.) Because of the above reasons, the similar display quality (in terms of brightness) cannot be obtained, unless the brightness of the backlight is tripled, for instance.
In reality, when quickly moving dynamic images are displayed, blurring occurs in the images. Further, to increase the response speed, a panel is subjected to rubbing not in the direction of the electrode but in the direction deviated by for example about 15 degrees from the direction of the electrode. If the rubbing is performed in the direction of the electrode, the rotational direction of the liquid crystal molecules in the middle of the electrodes is not stabilized as one direction, resulting in a longer response time. Therefore, by inclining the rubbing direction by 15 degrees, even after this process, the response time is twice that of the TN type. Through this process, the viewing angle characteristics are not perfectly symmetric, and some gray-level inversion occurs around the rubbing direction.
To explain this situation, the coordinate system of a polar angle θ shown in FIG. 7A and the azimuth angle φ shown in FIG. 7B are determined for the substrates 20 and 24, the electrodes 21 and 22, and the liquid crystal molecules 23 shown in FIGS. 7A and 7B. FIG. 8A shows the viewing angle characteristics of the panel, in which the gray scales are divided into eight levels from the white state to the black state, and the brightness variations are analyzed by varying the polar angle and the azimuth angle. The shadowed portions in the figure represent gray-level inversion, which are caused in the two azimuths (the 45-degree ranges of 60 to 105 degrees and 240 to 285 degrees in the azimuth angle φ). FIG. 8B shows the transmittance variations of the 8 gray-level displays with respect to the polar angle θ at an azimuth angle of 75 degrees, which causes inversion. The gray-level inversion is caused due to a drop in the white brightness.
In the IPS method, the gray-level inversion is caused due to a drop in the white brightness in the two azimuths, and the viewing angle characteristics deteriorate. By switching in the lateral direction, viewing angle characteristics equivalent to a multidomain panel, but the transmittance, the response speed, the productivity and the market price are all sacrificed. Particularly, a low response speed is not suitable for displaying dynamic picture images.

Liquid crystal display device having insulating patterns with width larger than gap in between


The present invention is an integrated isopropyl alcohol (IPA) and diisopropyl ether (DIPE) process. In this process, IPA, substantially free of DIPE, is formed in a hydration reactor by reacting an olefinic feedstock with water in a hydration reactor. The effluent from the hydration reactor is then contacted in a first separation unit with DIPE which was made in an etherification reactor. The resulting mixture is then passed to a second separation unit to separate the IPA from the DIPE product. The IPA is then fed to the etherification reactor to produce DIPE.

The need to eliminate lead-based octane enhancers in gasoline has provided an incentive for the development of processes to produce high octane gasolines blended with lower aliphatic octane boosters. Supplementary fuels are being examined by the petroleum refining industry. Lower molecular weight alcohols and ethers, such as isopropyl alcohol (IPA) and diisopropyl ether (DIPE), are in the boiling range of gasoline fuels and are known to have a high blending octane number. They are also useful as octane enhancers. In addition, by-product propylene from which IPA and DIPE can be made is usually available in a fuels refinery, typically as a C.sub.3 aliphatic stream which is rich in both propylene and propane.
The preparation of DIPE from propylene chemically proceeds by two sequential reactions where propylene is first hydrated to IPA (1) followed by reaction of the alcohol with the olefin (2) or bimolecular reaction of the alcohol (3) (Williamson synthesis) according to the equations, EQU CH.sub.3 CH=CH.sub.2 +HOH.rarw..fwdarw.CH.sub.3 CHOHCH.sub.3( 1) ##STR1##
When DIPE is produced via reaction (3), twice as much IPA is required than when DIPE is produced via reaction (2). Since hydration reactions, for example reaction (1), are generally more difficult to perform than etherification reactions, the production rate of the alcohol limits the overall sequence and it is desirable to limit the formation of DIPE from reaction (3) and increase the formation of DIPE from reaction (2). Side reactions that can occur in this process are the reaction of propylene with itself to make C.sub.6 olefins and the reaction of C.sub.6 olefins with propylene to make C.sub.9 olefins. These reactions are considered undesirable since they result in low value polygasoline with low octane and no oxygen content.
The synthetic production of IPA and DIPE is well known. Among the earliest processes for the production of IPA and DIPE were the so-called indirect hydration processes. In the indirect hydration process, a selected olefin feed is absorbed in a concentrated sulfuric acid stream to form an extract containing the corresponding alkyl ester of the sulfuric acid. Thereafter, water is admixed with the ester-containing extract to hydrolyze the ester and to form the desired alcohol and ether which are then recovered, generally by stripping with steam or some other heating fluid. A diluted sulfuric acid stream is thereby produced. This acid stream is then generally treated to concentrate the sulfuric acid stream for recycle to the absorption stage.
In the indirect hydration process, the use of sulfuric acid as a catalyst presents certain problems. First, severe corrosion of process equipment can occur. Second, separating the produced ether from the sulfuric acid can be difficult. Third, a substantial quantity of waste sulfuric acid is produced in the concentration of the catalyst for recovery. Because of these problems, it has been found that the process of synthesizing DIPE by using concentrated sulfuric acid is not commercially viable. Clearly, there was a need for a more direct manner of bringing about the hydration reaction.
This need was addressed by so-called direct hydration processes using solid catalysts. In the direct hydration process, an olefinic hydrocarbon such as propylene is reacted directly with water over a solid hydration catalyst to produce an intermediate IPA stream from which the product DIPE can be formed. Development work using direct hydration focuses on the use of solid catalysts such as active charcoal, clays, resins and zeolites. Examples of olefin hydration processes which employ zeolite catalysts as the hydration catalyst can be found in U.S. Pat. Nos. 4,214,107, 4,499,313, 4,857,664 and 4,906,187.
The use of zeolites as hydration catalysts has the disadvantage of being expensive in comparison to other catalysts, for example, ion exchange resin catalysts. Also, in comparison to ion exchange resin catalysts zeolites do not operate as well at the relatively low temperatures required for hydration and etherification. Furthermore, zeolites have a strong tendency to form DIPE from reaction (3) instead of reaction (2). They also have a strong tendency to produce substantial amounts of undesirable polygasoline from the reaction of propylene with itself.
In many of the direct hydration processes developed by the refining industry, the hydration reactor is operated to produce both IPA and DIPE. In other words, the hydration of olefins to IPA and the etherification of IPA to DIPE occurs in a single reactor. After separation, the IPA is then recycled to the hydration reactor to produce additional DIPE. For example, in U.S. Pat. No. 5,102,428 (issued to Owen et al.) a C.sub.3 hydrocarbon feed stream comprising propylene and propane is fed along with water to a single hydration/etherification reactor containing an acidic catalyst. Both hydration and etherification reactions occur in this single reactor. The reactor effluent containing DIPE, IPA and propylene is then passed to a high pressure separator/extractor wherein the effluent is contacted by water to remove a substantial amount of the IPA. The resulting stream is flashed to remove propylene and fractionated to remove the remaining IPA. The aqueous IPA stream and the IPA recovered from fractionation are recycled to the hydration/etherification reactor for reuse. Unconverted propylene is polymerized to form polygasoline using a metallosilicate catalyst rather than recycled to the hydration/etherification reactor to produce additional IPA. This is highly undesirable since it limits the oxygenate production and produces substantial amounts of polygasoline which has low octane.
Using a single reactor for hydration and etherification can present a problem because the conversion of propylene and water to IPA takes place at a higher temperature than the conversion of IPA to DIPE. By having both reactions take place in a single reactor, the conversion of IPA to DIPE must occur at a higher temperature than desired and the conversion of IPA to DIPE is decreased.
Some direct hydration processes use two reactors so that any unreacted IPA formed in the first reactor can be sent to a second reactor to further etherify the IPA. For example, in U.S. Pat. No. 4,935,552, propylene, water and IPA are introduced to a first reactor containing a hydration/etherification catalyst to form an effluent which consists of IPA, DIPE and unreacted reactants. The effluent is then flashed to remove propylene and extracted with water to transfer the IPA to the aqueous phase. A portion of the resulting hydrocarbon phase containing high purity DIPE is recycled to the first reactor in order to control the temperature. This is undesirable since recycling a product in an equilibrium-limited reaction will reduce conversion of the reactants, thereby limiting production of IPA and DIPE. The aqueous IPA phase is passed to a second reactor (catalytic distillation unit) where additional etherification of the IPA to form DIPE takes place. In this second reactor, DIPE is made exclusively by reaction (3) since the propylene has all been removed. This means the first reactor has to make twice as much IPA to make the same amount of DIPE.
U.S. Pat. No. 5,144,086 (issued to Harandi et al.) discloses an integrated IPA and DIPE process that has two separate reactors, one for the exclusive formation of IPA and the other dedicated to etherification. In this process, propylene and water are introduced to a first hydration reactor containing an acidic hydration catalyst to produce an IPA-containing effluent that is substantially free of DIPE. After separating the effluent stream to remove the propylene and propane, the IPA-containing stream is passed to an etherification reactor containing a zeolite catalyst to produce an etherification effluent that contains DIPE, water and propylene. This process produces DIPE by reaction (3) rather than reaction (2) and therefore requires twice as much IPA to be made. The effluent from the etherification reactor is then fractionated to produce the DIPE product. This process suggests using one separation zone (distillation column) to remove C.sub.3 hydrocarbons and water from the intermediate IPA stream and another separation zone to remove C.sub.3 hydrocarbons and water from the DIPE product stream, resulting in a considerable addition to the capital expense of the integrated process.
There is a need for an integrated IPA and DIPE process which utilizes common separation zones to remove C.sub.3 hydrocarbons and water from the IPA and DIPE streams, and which maximizes conversion in each stage, minimizes formation of DIPE from dehydration (reaction 3), and minimizes polygasoline formation. And it is the object of this invention to fill this need.

Integrated process for producing diisopropyl ether from isopropyl alcohol


A training mannequin for sparring and self-defense training is disclosed which employs a life-size mannequin torso in place of the traditional punching bags. The mannequin torso provides more realistic training and provides anatomically correct references as well as lifelike reaction and feel when struck. The mannequin is made from an outer skin filled with a flexible interior foam. The outer skin is formed from a flexible material which returns to its original shape even after it is deformed by a strong blow. This resilience allows the mannequin to absorb virtually unlimited blows without losing its shape, structure or feel. Further, the three dimensional nature of the mannequin allows training in realistic circumstances and from angles not possible with traditional punching bags.

Traditionally, punching bags are formed from an outer shell filled with padding. The bags are usually geometrically shaped (for example, cylindrical, spherical or rectangular) and suspended with chains or the like from an overhead support. The standard cylindrical punching bag, while a useful training tool, does not provide anatomical reference points or lifelike feel and feedback when punched or kicked. Further, in sparring situations an opponent's shoulders are almost never square to the combatant. A right-handed opponent will be turned at an angle with his left shoulder closer to the combatant than his right. Opponents can also either be right-handed or left-handed. Left-handed opponents provide a much different target than do right-handed opponents, primarily due to the different stance which turns the opponent's shoulders opposite direction than those of the right-handed opponent. Traditional bags cannot simulate stance differences based on predominant hand. This limits their usefulness as training tools.
Additionally, different techniques are required for "fighting inside" than are used for normal sparring. "Fighting inside" can loosely be defined as encounters where the opponents are very close to one another or well within the reach of each other. When fighting inside, combatants usually assume a much more defensive posture which involves bending at the waist to give the opponent a smaller target to hit. Prior training bags are unable to simulate this technique and are inadequate for training a fighter to fight inside.
While three dimensional mannequins have existed for years, current mannequins are unsuitable for sparring and training for a variety of reasons. Most traditional mannequins are made from a hard plastic material. Hard plastic mannequins are unacceptable for sparring and training as they could injure the person punching or kicking them. Additionally, the hard nature of the mannequins would not simulate the feel of striking a human body.

Three dimensional training mannequin with lifelike reaction and feel for sparring and self-defense training


Briefly, a radio receiver architecture and a method of measuring a power of a received signal to provide a first measurement, measuring a power of an assigned channel signal to provide a second measurement and adjusting a power of an input signal of an analog to digital converter according to a difference between the first and second power measurements.

Wideband Code Division Multiple Access (WCDMA) receiver may include a radio unit (RU) and a digital base band unit (DBBU). The RU may include, among other components, an analog filter and a sigma delta analog to digital converter (SD-ADC). The analog filter may be used as anti-aliasing filter (AAF) with limited channel selection capabilities.
The DBBU may include a decimation filter coupled to a matched filter and a power measurement unit to measure a power level of a signal at the output of the matched filter. An automatic gain controller (AGC) may receive the power measurement and may adjust a gain of amplifiers at the RU to achieve optimal signal spread at an input of the sigma-delta ADC.
More specifically, the measurement unit may measure an assigned channel power after the digital matched filter. This measurement may be compared to a predetermined power (e.g., a threshold). The AGC may compensate for the difference between the measurement of the assigned signal and the threshold, by sending a gain command to the amplifiers at the RU. As a result of the RU limited selectivity, high interferences from adjacent channels may be present at the ADC input. The power of these interferences is not reflected in the power measurement at the matched filter output and, thus the gain is not changed and the ADC input signal may be clipped.
Known radio receiver architectures may prevent the undesired effect described above by expanding the dynamic range of the SD-ADC and employing an AGC that leaves a headroom at an upper part of an amplitude of the input signal of the SD-ADC for adjacent channel interferences. However, the known radio receiver architectures may have at least two disadvantages. The first disadvantage may be that the radio receiver architecture requires a sigma delta ADC with a high dynamic range (e.g., ˜70 dB). The second disadvantage may be that a desired signal is always spread over a lower part of the SD-ADC dynamic range where the signal may be more susceptible to implementation impairments.
It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements.


An image forming apparatus which utilizes an intermediate transfer member. Plural toner images, for example of different colors, can be superimposed on the intermediate transfer member, and then can be transferred to a paper sheet. A discharging device is provided for discharging a charge applied to the intermediate transfer member. Further, a value of a voltage provided by this discharging device and/or a voltage provided for a transfer bias is proportional to an actual surface potential on the intermediate transfer member, which is proportional to the number of times toner images have been formed on the intermediate transfer member prior to transfer to the paper sheet. For example, if a full color toner image is formed on the intermediate transfer member, which may result from four operations of transferring individual toner images onto the intermediate transfer member, a voltage provided by the discharger and/or by a transfer bias device will be higher than that if only a monocolor image has been formed on the intermediate transfer member. Further, the image forming apparatus can be operable to form images on thicker paper, and in this instance a drive speed of devices in the image forming apparatus can be reduced, and a voltage applied to a pre-charger can also accordingly be reduced. The image forming apparatus can also include a cleaning device from the intermediate transfer belt, and the functions of both the intermediate transfer member discharging device and a cleaning device can be combined in one brush roller.

1. Field of the Invention
The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile, etc., and more particularly to an image forming apparatus in which an intermediate transfer member is used.
2. Discussion of the Background
A background image forming apparatus includes the following elements: an intermediate transfer member for bearing a toner image transferred from an image bearing member, a primary transfer charger for applying a charge to the intermediate transfer member for transferring the toner image from the image bearing member to the intermediate transfer member, a secondary transfer charger for applying a charge to a final transfer member, e.g. a paper sheet, for transferring the toner image from the intermediate transfer member to the final transfer member and an intermediate transfer member discharging device for removing a charge from a surface of the intermediate transfer member which has transferred the toner image to the final transfer member. In such an image forming apparatus, a surface potential of the intermediate transfer member is made uniform by removing the charge from the surface of the intermediate transfer member with the intermediate transfer member discharging device to prepare for a next primary transferring operation from the image bearing member to the intermediate transfer member.
However, in some cases in the above-mentioned background image forming apparatus, the surface potential of the intermediate transfer member will not be at a desired predetermined potential, or an irregular potential remains after removing the charge from the intermediate transfer member with the intermediate transfer member discharging device. These states of defective discharging deteriorate any subsequent transfer process from the image bearing member to the intermediate transfer member.
As a result of an investigation of a cause of the defective discharging on the intermediate transfer member made by the inventors of the present invention, it has been determined that a main cause of the defective discharging is significant unevenness of the surface potential of the intermediate transfer member whose charge has not been effectively removed by the intermediate transfer member discharging device.
This unevenness may particularly occur if the image forming apparatus is a color image forming device constructed so that the primary transferring operation is performed a plurality of times to superimpose toner images of various colors, which have been formed on the image bearing member, onto the intermediate transfer member, and in which then the toner images superimposed on the intermediate transfer member are transferred to the final transfer member at one time. In this case, the surface potential of the intermediate transfer member whose charge has not been removed by the intermediate transfer member discharging device may be uneven. Further, the degree of unevenness may depend on the number of the toner images superimposed on the intermediate transfer member, in other words, the number of times the primary transfer to the intermediate transfer member is executed.
Further, in such a background image forming apparatus, a transfer condition for transferring the toner image on the intermediate transfer member to the final transfer member is set to be almost at a center of a preferable transfer range in which a transfer rate to the final transfer member is normally set to a predetermined value or greater. A difference between a set value of this transfer condition and an upper limit of the preferable transfer range or a lower limit thereof corresponds to a transfer allowance for transferring the toner image on the intermediate transfer member to the final transfer member. As this difference is increased, the transfer allowance becomes greater.
If a toner image which has passed through a primary transfer section, which transfers the toner image from the image bearing member to the intermediate transfer member, includes portions having different amounts of adhering toner, unevenness of a charged amount occurs in the toner image on the intermediate transfer member. For example, if the toner image on the intermediate transfer member includes a solid portion and a halftone portion, a charged amount of the solid portion may be lower than that of the halftone portion. Furthermore, for example, in a color image forming apparatus is used, a charged amount of a portion where toner of a plurality of colors is superimposed in the toner image on the intermediate transfer member is lower than that of a portion where toner of only a single color adheres to the intermediate transfer member.
In addition, unevenness of the charged amount in the toner image is sometimes caused by a peeling discharge which occurs downstream adjacent to the primary transfer section in a surface moving direction of the intermediate transfer member after the toner image has passed through the primary transfer section for transferring the toner image from the image bearing member to the intermediate transfer member.
If there is unevenness of a charged amount in the toner image on the intermediate transfer member as described above, the toner image contains portions having different transfer characteristics. If an attempt is made to transfer all the portions having the different transfer characteristics to the transfer member under the same transfer conditions, a range of the transfer condition over which the entire toner image can be transferred at a transfer rate greater than a predetermined value is narrowed. As a result, the transfer allowance for the entire toner image is decreased, and thereby the toner image cannot be transferred stably to the final transfer member.
Referring to FIG. 9, a graph of transfer characteristics is shown with curved lines a and b indicating relationships between a transfer current and a transfer rate for a solid portion and a halftone portion, respectively. Widths indicated by reference numerals A and B in FIG. 9 correspond to ranges of a transfer current which allows respective portions to be transferred to a final transfer member at a transfer rate of 80% or greater, and the transfer allowances are relatively high. However, a range of a transfer current which allows both of these two portions to be transferred at a transfer rate of 80% or greater is narrow as indicated by reference numeral C in FIG. 9 due to a deviation of the two curves a, b, and therefore a transfer allowance is lowered. That is, an overlapping of curves A and B, which is a range which allows both solid and halftone image portions to be effectively transferred, is narrow, which thereby lowers a transfer allowance.
As a further drawback, a background image forming apparatus requires both an intermediate transfer member discharging device, such as a corona discharger, for removing charges on a surface of the intermediate transfer member and a cleaning device, such as a cleaning blade, for removing deposits on the surface of the intermediate transfer member individually, and therefore it is difficult to reduce the cost of such a background device.

Image forming apparatus which removes a surface potential of an intermediate transfer member


A startup method for a fluidized catalytic cracking (FCC) unit operating with a magnetic catalyst separation means is disclosed. Magnetic strength, or separation severity, is maintained or increased until most of the catalyst has passed through the magnetic separation unit. After this point, magnetic flux and/or centrifugal forces, are decreased for lined-out operation. Preferably a MagnaCat.RTM. catalyst separation unit is used for magnetic fractionation of catalyst.

The process for magnetic separation of catalyst from a fluidized catalytic cracking or similar unit was recently commercialized. The magnetic separation process is described in one or more of U.S. Pat. No. 4,406,773 to Hettinger, Jr. et al.; U.S. Pat. No. Re. 35,046 to Hettinger, Jr. et al.; U.S. Pat. Nos. 5,147,527 to Hettinger, Jr. et al.; 5,171,424 to Hettinger; 5,190,635 to Hettinger; 5,198,098 to Hettinger, Jr.; 5,230,869 to Hettinger et al.; 5,328,594 to Hettinger; 5,364,827 to Hettinger et al.; 5,393,412 to Hettinger; and 5,538,624 to Hettinger; all of which are hereby incorporated by reference.

Startup of magnetic separation process in an FCC unit


A display apparatus has pixels arranged along rows and columns in which each pixel is defined by a pair of opposed electrodes. The pixels are provided by sub-pixels with color filters of different colors wherein integral light quantities of the same color sub-pixels of adjacent pixels are different. The display apparatus is capable of selecting a first display operation in which a single pixel is displayed as one display unit, as well as a second display operation in which at least two adjacent pixels are combined to form one display unit.

1. Field of the Invention
The present invention relates to a display apparatus for displaying images and characters and, more particularly, to a matrix display apparatus which divides a pixel into sub-pixels to display multicolor and multi-gradation.
2. Related Background Art
Conventional matrix displaying apparatuses are capable of dividing a single pixel into sub-pixels so that multi-values are displayed using the pixel. As shown in FIG. 12 , when the area of a single pixel is divided in a ratio of 3 to 2, the pixel is capable of displaying four values 0%, 40%, 60% and 100%. Also, when the area of a pixel is divided in a ratio of 1:1:1 and red, green and blue color filters are placed over the divided areas, eight colors can be displayed. When pixels are divided in an appropriate ratio, they are capable of displaying 2.sup.N colors or 2.sup.N gradations, where N is the number of pixels divided.
Because each pixel is divided into sub-pixels in the same ratio, when the above conventional apparatus displays a single piece of information using a plurality of pixels, there are a plurality of sub-pixels of the same color and gradation in a single display unit. Therefore, the number of gradations which can be displayed is much fewer than 2.sup.N. In other words, the conventional ratio at which a single pixel is divided into sub-pixels is inappropriate.

Display apparatus with pixels having subpixel regions


Chromogenic solvent detectors are used to detect and map the presence of organic solvent-containing materials on a surface. The detector need only be applied to the surface to be tested. When removed, the dark areas on the detector correspond to those areas of the surface where an organic solvent-containing material was present. This method can be used to test the release properties of a release film.

Chromogenic record materials are well known in the art and are described in a number of patents, for example, U.S. Pat. Nos, 3,539,375; 3,674,535; 3,746,675; 4,151,748; 4,181,771; 4,246,318 and 4,470,057 which are incorporated herein by reference. In these systems, basic chromogenic material and acidic developer material are contained in a coating on a substrate which, when heated to a suitable temperature, melts or softens to permit the materials to react, thereby producing a colored mark. The use of solvents to induce chromogenic markings for mapping the solvents' presence on a surface would be highly desirable.
A method for quickly and easily detecting and mapping the presence of organic solvent-containing materials on a surface would be advantageously used in many applications in the manufacturing arts. A method for detecting and mapping the presence of organic solvent-containing materials on surfaces having different shapes and contours would be especially useful. A particular application would be to provide a quick and easy method of testing the release properties of a release material by using a chromogenic solvent detector.

Method of detecting and mapping organic solvent-containing materials on a surface


An erasing current is distributed to reduce a load of an internal power circuit and to decrease the number of drivers for erase. A semiconductor data processing device has: a memory array having nonvolatile memory cells arrayed in a matrix and divided into a plurality of erase blocks each instructed to be erased together; and a control circuit, wherein the control circuit controls both of two kinds of erasing voltages applied to the nonvolatile memory cell in the erase block instructed to be erased together to select an erase sector from the erase block for performing erase for each erase sector, thereby performing the erase for each erase sector in time division. Time division erase can distribute an erasing current. Two kinds of erasing voltages are used to select the erase sector. No specific drivers need be provided for each erase sector.

The present invention relates to a semiconductor data processing device having electrically erasable and writable nonvolatile memory cells, more specifically, to a technique for erasing the nonvolatile memory cells. For instance, the present invention relates to a technique effective to be applied to a flash memory or a microcomputer over which the same is mounted.
Patent Reference 1 describes a technique in which a flash memory array is divided into sectors to sequentially perform erase for each of the sectors, and before completely erasing the memory cells in one sector, erase of the memory cells in another sector is started to shift erase of the sectors in time for distributing a peak current at erase.
Patent Reference 2 describes a technique in which a flash memory array is divided into blocks to sequentially perform application of an erasing voltage for each of the blocks, thereby distributing a peak current at erase.
Patent Reference 3 describes a technique in which a chip has a plurality of memory arrays, erase is performed plural times for time division erase, thereby distributing a peak current at erase. The memory arrays are erased together. The memory arrays are divided into groups which are erased together. The number of memory arrays in the group is increased corresponding to the progress of erase to shorten erase time.
Patent Reference 4 describes a technique in which a memory array is divided into blocks to perform time division erase for each of the blocks, thereby distributing a peak current at erase. At erase, erase verify is performed for each of the blocks, thereby preventing over erase.
Patent Reference 5 describes a technique in which a memory array is divided to perform time division erase for each division, thereby distributing a peak current at erase for preventing the erasing voltage level from being lowered and for reducing the load of an internal booster circuit.
Patent Reference 6 describes a technique in which a memory array is divided into blocks, part or all of the memory array has a plurality of subdivided blocks to perform erase for each of the subdivided blocks, thereby distributing a peak current at erase.    [Patent Reference 1] Japanese Unexamined Patent Publication No. Hei 10 (1998)-199271    [Patent Reference 2] Japanese Unexamined Patent Publication No. Hei 6 (1994)-150677    [Patent Reference 3] Japanese Unexamined Patent Publication No. Hei 6 (1994)-103790    [Patent Reference 4] Japanese Unexamined Patent Publication No. Hei 4 (1992)-228193    [Patent Reference 5] Japanese Unexamined Patent Publication No. Hei 2 (1990)-232899    [Patent Reference 6] Japanese Unexamined Patent Publication No. Hei 3 (1991)-105795


Tools and methods for measuring resistivity are provided. The tool for measuring resistivity in a formation comprises a receiver module comprising a first electromagnetic signal receiver and a second electromagnetic signal receiver; a first electromagnetic signal transmitter removably coupled to one longitudinal end of the receiver module; a second electromagnetic signal transmitter removably coupled to the other longitudinal end of the receiver module; and each of the first and the second electromagnetic signal receivers configured to receive electromagnetic signals propagating in the formation from the first and the second electromagnetic signal transmitters.

A drill string consists of a bit, followed by a series of inter-connected downhole tools. Many of these tools perform measurements on the surrounding geological formations. The measurement results are transferred to the directional unit which manages the communication of this data to the surface. Based on this data, the human operator decides what must be done to steer the entire drill string towards the desired target.
Above the downhole tools, there is a long series of pipe sections reaching to the surface and the drilling rig. Mud is pumped down this pipe at a high pressure and this mud turns the mud motor and squirts through the bit to help cut the borehole and clear the cuttings.
The three most basic electromagnetic properties that all materials possess are electric permittivity (ε), magnetic permeability (ρ), and conductivity (σ). The inverse of conductivity is resistivity ρ=1/σ, which is measured in units of Ω·m and is responsible for the electrical resistance of materials. For example, given the cross-sectional shape of a wire, its length, and a material's resistivity, the total electrical resistance of the wire can be calculated.
In the context of drilling, the electrical resistivity of normal salt-water bearing formations is quite low (<10 Ω·m) while that of formations containing natural gas and oil is quite high (>100 Ω·m). Accordingly, it is valuable to measure the resistivity of the environment surrounding a drill string. One manner of making the resistivity measurement would be to place two probes on the outside of the drill collar, put a voltage across the probes, and measure the current. The ratio of voltage to current is resistance and, with some knowledge of the current path, the resistivity could be estimated.
These types of measurements can have disadvantages. For instance, the space directly around the drill collar is surrounded by drilling mud and it would be beneficial to measure the resistivity of the surrounding material in a way that is minimally influenced by the drilling fluid. It would also be beneficial to estimate the resistivity as a function of depth such that the presence of a material layer can be sensed without actually penetrating it.
A need therefore exists for an improved system and method for measuring resistivity in a formation. Accordingly, a solution that addresses, at least in part, the above and other shortcomings is desired.

Tuned probe style propagation resistivity tool


A seal for use with an electrical connector having a flange which is dimensioned to confront a mounting panel around a cutout in the mounting panel comprises one-piece seal member including a conductor seal and a flange seal. The conductor seal is configured to sealingly engage conductors extending from the electrical connector, and the flange seal is configured to seal between the mounting panel and the flange when the electrical connector is mounted in the mounting panel.

A refrigerator often has an electrical connector mounted in a cutout in a panel to provide an interface between electrical devices on opposite sides of the panel. When the panel separates a refrigerated space from a non-refrigerated space, it is necessary to provide a good seal between the electrical connector and the panel in order to prevent exchange of heat and air between the spaces. Presently, a panel mount electrical connector in a refrigerator has a flange which is abutted against the panel. The panel is made from a plastic material, and the panel is often wavy or has other deviations in planarity, thereby causing gaps between the flange and the panel. Further, different panels may vary in thickness, thereby making it difficult to consistently maintain the flange against the panel. During assembly of the refrigerator, an insulative foam is injected over the warm side of the panel. If the panel is wavy or if the flange is not abutted against the panel, the foam will shoot through gaps between the connector and the panel, thereby causing mess and splatter inside the refrigerated space. This problem is exacerbated when wires extending from the connector are pulled and bent during assembly of the refrigerator, thereby cocking the connector in the cutout and causing a larger gap. A further problem exists in that the foam may enter the connector through gaps around the wires and may interfere with electrical reliability of the connector. The invention overcomes these problems by providing a panel mount electrical connector with a one-piece seal member which seals to both the conductors and the flange of the connector.


A hierarchical digital signature method is provided by which different levels of data elements of a data entry are processed in turn to derive function values (for example hash function values) for data elements in the level which are to form part of the digital signature. All function values for one level are combined in a further function to provide an additional function value, and the additional function value is used in the processing of data elements in the next level nearer to the root. This provides a digital signature which can use only selected data elements of a data entry, and which is not sensitive to the ordering of the data entry structure.

There are many applications in which a large amount of content is stored in a repository, with access to the data stored through a network such as the internet.
A data repository may take the form of a conventional database that stores content in records having a number of fields. In conventional databases, some of the fields are indexed so that data in the indexed fields is stored in a separate index. The separate index may be searched for specific search terms to identify records including those search terms.
The use of digital signatures is well known, in order to provide an indication that a data element originates from a genuine source. A digital signature of a message or data is a data object dependent on a secret key known only to the signer and on the content of the message or data being signed.
There are many known digital signature algorithms. A digital signature scheme can be with an appendix, so that the original message/data is input as part of the digital signature verification. Alternatively, digital signature schemes may be with message recovery, in which case the original message/data is recovered during the digital signature verification, for subsequent comparison with the unsigned message. A public key is used to read the signed message and thereby verify the authenticity.
The use of digital signatures for the content of data repositories is known. One common approach for performing digital signing of electronic content in document storage and archival systems involves the use of the entire content of the stored object in the calculation of a digital signature. This approach works well with the storage of data objects where there is no structure to the content of the object and where the only update process involved is through deletion or replacement of a whole object.
Storage of application data in a so-called "semi-structured" format has become common in archival storage devices, and this type of data does not meet the requirements outlined above.
So called "semi-structured" data has a structure which is not regular and does not have a fixed format. The data can quickly evolve. There is also a blurring between the structure and the data stored by the structure. The lack of a fixed schema and the lack of fixed information on the data structures makes the handling of such data difficult using conventional database technology.
Technologies are being developed to allow structure to be extracted from the data objects, with query execution techniques able to exploit this extracted structural information.
This type of data structure allows applications to define complex data objects through the use of semi-structured content. The data objects often consist of content placed in the data object on initial store coupled with annotations added later through a business process lifecycle. For example, a document publication and review process requires the ability to define and store the initial document, followed by the addition of annotations or notes during a review process, so that the content changes in data and in structure.
A semi-structured data store may for example comprise an Extensible Markup Language, XML, store. The stored data has a finer grained structure than the whole object. In this type of environment, updates may be made to an object that involve only specific properties or sub-elements in the archived object.
A digital signature prepared using the entire object does not then allow a third party to update the object. However, there may be instances when it is desirable for a third party to update sub-elements of a document without needing to apply a digital signature.

Method of digitally signing data and a data repository storing digitally signed data

Hewlett-Packard Development Company, L.P.


In accordance with the present invention, it has now been found that glycidyl epoxy resins containing substitution on the epoxide ring can be used with conventional epoxy curing agents and fluxing agents to produce underfill adhesives that are suitable for use with silver-based alloys. Owing to the structural similarity of the new materials to conventional epoxy resins, physical and material properties of the invention formulations are altered little, if at all, relative to products currently in use, and so are highly compatible with existing processes.

Epoxy resin-based fluxing underfill adhesives are widely used for the assembly of solder-bumped flip-chip devices. As these assemblies are heated in the region of 180-220° C. to reflow or melt the solder, the fluxing agent component of the adhesive cleans and removes oxides from solder surface promoting self-alignment, electrical connectivity and mechanical attachment of the chip to the substrate. During this process, the bumped chip is observed to undergo a controlled collapse as solder wets the contact pads located on the substrate surface and a solder joint is formed. To facilitate this process, it is important that curing of the epoxy be kept to a minimum until device collapse has occurred. Thereafter, it is desirable that curing be completed as quickly as possible.
Current epoxy formulations have been optimized for this process which generally employs lead-based solder alloys. However, due to toxicity and environmental concerns, no-lead solders, based on silver alloys, have been developed. These alloys typically melt at temperatures that are significantly higher than lead-based materials (i.e., 210-250° C.) and therefore fluxing formulations designed for lead-based processes are ineffective with silver-based alloys. The higher temperatures of the lead-free alloys cause significant curing of the adhesive compositions prior to and during fluxing and solder melting. As a result, device collapse and electrical connectivity are seriously compromised.
A need exists therefore, for fluxing adhesive formulations in which the onset of curing occurs at substantially higher temperatures than is possible with current epoxy systems, but yet retains other desirable features of the existing formulations.

Adhesive of substituted oxirane or oxetane compound with silver-based, lead-free solder


A dual mode drum brake assembly having an improved duo-servo parking and emergency brake lever mechanism includes a pivot lever pivotally supported relative to a first brake shoe and operatively coupled to exert an outward force on the first brake shoe when the parking brake is actuated. According to one feature of the invention, a hold down assembly extends through an aperture formed in a web of the first brake shoe, and through an aperture formed in the pivot lever to secure the first brake shoe to a backing plate and to pivotally connect the pivot lever to the web. According to another feature of the invention, an adjuster lever of a first strut member is pivotally supported on the first brake shoe, and the pivot lever is pivotally supported on the first brake shoe generally intermediate the first strut member and a second strut member.

This invention relates in general to a "dual mode" drum brake assembly which includes a hydraulically actuated service brake of the leading/trailing type, and a mechanically actuated parking and emergency brake of the duo-servo type.
One version of a dual mode drum brake is disclosed in Australian Patent No. 53,491. In this patent, a hydraulic actuator, used for applying the service brakes, is located adjacent the upper ends of a pair of brake shoes, while a fixed abutment is located adjacent the lower ends. This arrangement provides a service brake of the leading/trailing type. The brake further includes an upper strut which is located adjacent the hydraulic actuator and extends between the brake shoes, and which is provided with an automatic adjusting mechanism. A parking brake actuating lever is pivotally mounted on a lower end of one brake shoe, and an idle lever is pivotally mounted at an intermediate point on the other brake shoe. A lower strut extends between the brake shoes adjacent the lower abutment and is disposed between a lower end of the parking brake lever and a lower end of the idle lever. When pivoted, the parking brake actuating lever extends the effective length of the lower strut and pivots the idle lever to initiate duo-servo actuation of the parking brake
Other versions of dual mode drum brakes are disclosed in U.S. Pat. No. 3,400,787 to Keller et al., U.S. Pat. No. 3,709,334 to Kondo et al., U.S. Pat. No. 4,364,456 to Colpaert, and U.S. Pat. No. 4,678,067 to Thompson.


A method of searching for a scene based on a stream of images archived in a video surveillance database including: a first phase of preprocessing prior to archiving of the images including extracting generic information from the images of the stream, systematically annotating the scenes of the images by at least one indication defined as a function of the generic information, and indexing the scenes of the images based on information extracted from the indications originating from one or more streams; a second phase of investigation by preselecting video segments from the stream of images including the annotation indications associated with the images; and a third phase of searching for a particular scene based on at least one additional characteristic not forming part of the annotations associated with the preselected video segments.

Video images are increasingly used in industrial applications for process monitoring and supervision and in video surveillance applications for public and private sites. These applications generally use a network of cameras carefully arranged so as to provide reliable images at different points of the monitored area. The images provided by the different cameras are compressed, then stored in a video database for later use. In most applications, in particular in the video surveillance field, this use requires that a large volume of video images be processed, in particular when the network includes a large number of cameras spread out over a large area, such as a town, for example. The quantity of stored images quickly becomes too large for an operator to be able to perform a quick and effective analysis of the images in order to extract the actions or objects that are relevant to the considered application.
In practice, an investigation may require viewing and/or processing several tens of thousands of hours of video. It is then difficult to find the desired information if no prior indexing of the videos was done upon acquisition. Furthermore, the videos available during the search are those that were stored, therefore compressed, and no longer have the optimal image quality for the richest possible extraction of information.
In the prior art, there are systems generating alarms on predefined events or indications. However, in some applications, the events and indications generating the alarms can be insufficient to quickly and effectively navigate through the archives looking for objects (individuals, vehicles) of a nature to provide relevant information. This is the case for example when looking for suspects in a crowd at various points of an area monitored by cameras.
One drawback of current video surveillance systems is related to the fact that they deal solely with current events and generate alarms for predefined events. The notion of "memory" of such a system is limited to the videos recorded and alarms detected.
The systems do not make it possible to find an event that did not generate an alarm when it occurred, but has become decisive in the context of a later investigation.
A first aim of the invention is to organize the memory of such systems so that they allow an effective investigation by limiting the amount of data to be analyzed by the operator, and by systematically annotating the streams of images obtained by the cameras in order to enable a quick selection of video sequences that are relevant for the investigation.
A second aim of the invention is to provide material tools and software enabling the operator to quickly and effectively navigate the video archives using systematic indexing making it possible to extract the information on the stream before compression to benefit from maximum image quality.

Method of optimizing the search for a scene on the basis of a stream of images archived in a video database

European Aeronautic Defence and Space Company—Eads France


An opto-electronic component includes a housing, a radiation-emitting semiconductor chip and a radiation-detecting semiconductor chip. A first cavity and a second cavity are formed in the housing, wherein the radiation-emitting semiconductor chip is arranged in the first cavity and is cast by means of a first casting compound. The radiation-detecting semiconductor chip is arranged in the second cavity and cast by means of a second casting compound, wherein absorber particles are embedded in the second casting compound which are suitable for at least partially absorbing the radiation emitted by the radiation-emitting semiconductor chip.

It is known to design components comprising a radiation-emitting semiconductor chip and a radiation-detecting semiconductor chip. However, these devices conventionally comprise semiconductor chips arranged in separate housings and separately from one another on a printed circuit board, for example. As a result, however, such devices usually disadvantageously require a large space requirement and large component parts. That in turn is usually reflected disadvantageously in the production costs and component costs.
It could therefore be helpful to provide a compact component and at the same time reacts flexibly to environmental influences. Furthermore, it could be helpful to provide a method of producing such a component which is cost-effective, and to provide a flexible and at the same time reliable use of such components.

Optoelectronic semiconductor component, method for producing same and use of such a component


A method, system, and computer program product for encapsulating a packet within a virtualized network. The method includes writing one or more first translation control entries (TCEs) from a TCE table of a client system to a TCE table of a host system, and writing one or more second TCEs to the TCE table of the host system. The first TCEs indicate a location within the client system of payload data for the packet, and the second TCEs indicate a location within the host system of at least one of header and footer information to be included with the payload data.

The present invention relates to communications in packet-based networks, and more specifically, to encapsulating packets transmitted on virtual networks.
Traditionally, transmitting data between virtual client devices on virtual networks requires copying the data from the sending virtual client to a host device. The host device performs the encapsulation of the data before transmitting the data out on the physical network using a physical input/output (I/O) adapter, such as a network adapter. The transmitted packets are received at various other physical I/O adapters, which route the packet data to the destination virtual client.

This patent is subject to a terminal disclaimer.

System and method for packet encapsulation wherein translation control entries (TCEs) may redirect DMA for software defined networks

INTERNATIONAL BUSINESS MACHINES CORPORATION


A litter box shell for receiving at least one litter box therein comprises a substantially rectangularly shaped housing. The housing incudes a bottom wall, two opposing side walls, two opposing end walls and an open top. One of the opposing side walls has an opening formed therein which is of a sufficient size to allow a cat to pass therethrough. Each of the end walls includes a handle located adjacent the open top for facilitating the lifting and transporting of the litter box shell.

The present invention is directed toward a litter box shell and, more particularly, to such a litter box shell that is designed to receive one or more litter boxes therein and prevent litter from exiting the same.
Litter boxes are provided for the normal daily care of indoor cats. Litter boxes typically include a bottom wall, opposing side and end walls, and an open top. Before use, litter, which is comprised of a plurality of loose granular particles, is poured into the litter box. An undesirable consequence associated with most litter boxes is that cats often kick litter over the walls of the litter box and onto the floor both before and after use. Accordingly, the pet owner is constantly picking up the loose particles of litter that have been scattered on the floor. Furthermore, many cats are exceedingly shy and are uncomfortable with using a completely open litter box while people are present.
In recognition of the foregoing, closed litter boxes have been proposed that include a bottom wall, encircling side walls which extend upwardly from the bottom wall, and a top cover portion. At least one of the side walls has an opening formed therein for allowing a cat to enter or exit the litter box. See, for example, U.S. Pat. Nos. 4,940,016, 5,129,364, 5,178,100, 5,211,134 and U.S. Design Pat. Nos. 248,333 and 276,752. Such litter boxes are effective in reducing the amount of litter that can be thrown from the same. However, most cats do not prefer closed litter boxes because odors get trapped therein and cats are very clean, particular animals. Furthermore, it is difficult to clean these substantially closed boxes.
Litter boxes have also been proposed that include a bottom wall, an open top, and two or three walls of a height sufficient to somewhat reduce the amount of litter that can be thrown from the same. See, for example, U.S. Pat. Nos. 3,310,031, 3,890,931, U.S. Design Pat. No. 203,929 and an advertisement in the October 1995 issue of Cats. While the higher side walls in each of these proposed litter boxes may lessen the amount of litter that could be scattered onto the floor by a cat, each has an opening formed in at least one of the walls which is large enough to allow a significant amount of litter to be kicked from the litter box. Another problem associated with these litter boxes is that they are cumbersome to lift and transport when it is time to remove old litter therefrom and clean the interior of the same.