A system and method for processing geometry is provided which reduces the amount of memory needed for processing the geometry while improving the processing speed. The system and method deliver vertices in sequence to a vertex queue so that data in the vertex queue is freed as it is delivered and only minimal intermediate results are stored. By this incremental evaluation, less memory space is needed because input data is freed as it is used to compute results so that only small portions of intermediate results exist at any time. In another aspect of the present system and method, the vertices are maintained in the proper sequence so that sorting operations can be eliminated. More particularly, a sorted vertex queue and an unsorted vertex list are utilized so that resorting of the entire vertex list may be prevented. The use of sorted vertex queue and unsorted vertex lists are particularly useful when reading or collecting input data by allowing data to be efficiently stored and managed. In addition, a compressed format for storing geometry is utilized based on the fact that much information can be rederived from a sorted and reduced vertex queue.

A geometry engine is generally defined as a set of basic routines for processing integrated circuit geometry, and examples of some basic routines include Boolean operations (And, Or, AndNot), sizing operations (Grow and Shrink), and transformation operations (Translation, Rotation, and Mirroring). The geometry engine is particularly suited to VLSI design for checking design rules and fracturing the integrated circuit layout.
Some examples of Boolean operations that may be performed by a geometry engine on two geometric areas (A and B) are illustrated in FIGS. 1(a)-1(c). In FIG. 1(a), an And operation is performed on the two geometric regions A and B and the resulting region from this operation is outlined by the thick line. An Or operation is performed on the two geometric regions A and B in FIG. 1(b) with the region resulting from this operation being outlined by the thick line. In FIG. 1(c), an A AndNot B operation is performed on the two geometric regions A and B with the resulting region contained within the thick line.
Some examples of sizing operations that may be performed by geometry engines are illustrated in FIGS. 2(a) and 2(b). In FIG. 2(a), a Grow operation by an amount .DELTA. is performed on the shaded geometric regions so that all of the edges are moved outward by the fixed amount .DELTA. to achieve the geometric region outlined by the thick line. In FIG. 2(b), a Shrink operation is performed on the shaded geometric regions so that all of the edges are moved in by the fixed amount .DELTA. to produce the geometric regions outlined by the thick line. The Grow and Shrink operations are often used in design rule checking for the integrated circuit design to determine whether two or more geometric regions are properly spaced within the design rules.
Geometry engine systems having representations of various bases are known and include geometric based representations by contiguous polygons as illustrated in FIGS. 3(a) and 3(b), geometric based representations by non-overlapping quadrilaterals (rectangles or trapezoids) as illustrated in FIGS. 3(c) and 3(d) and geometric based representations by vertices as illustrated in FIGS. 3(e) and 3(f). While these known representations have been used in integrated circuit design with success, drawbacks and problems are associated with each representation. For example, geometric based representations by contiguous polygons create memory and speed problems because awkward representations typically result which are cumbersome to manipulate. The geometric based representations by non-overlapping quadrilaterals introduce false edges where non-overlapping quadrilaterals are joined together which also generate awkward representations. The known geometric based representations by vertices create problems due to large memory requirements and generally slow processing speeds. Although a potential problem of geometric based representations by vertices is that these representations are not well suited to arbitrary-angle geometries, this does not present a problem in many integrated circuit design applications because integrated circuit designers typically design at right angles to avoid arbitrary angle geometries which simplifies the design and optimizes some photolithography processes.
Of these known representations, the vertex based representation systems generally provide the most advantages for integrated circuit design applications. One such advantage provided by vertex based representations is that simple and consistent data types may be used. For instance, 16 possible data combinations in each quadrant for a vertex may be reduced to 10 possible data combinations for analysis purposes. These 10 possible combinations are illustrated in FIGS. 4(a)-4(j) and include the four concave placements of data at a vertex (FIGS. 4(a)-4(d)), the four convex placements of data at a vertex (FIGS. 4(e)-4(h)), and the two opposed data placements at a vertex (FIGS. 4(i) and 4(j)) which are termed complex placements. Another advantage of the vertex based representation is that no false features of the geometry are generated. An absence of false features allows less memory and processing time to be used as compared to the geometric based representation by quadrilaterals which generates extra construction lines for edges that do not exist. As a result, less processing time and memory space is needed for performing basic routines with vertex representations by avoiding such construction lines. Processing by vertex based representations also generates straightforward inter-geometry interactions so that less processing time of basic routines is necessary in comparison to polygon based representations where complex and multiple figures are used which leads to complex geometric interactions. Vertex based representations also allow routines and operations to be easily performed at the corner represented by the vertex.
Nevertheless, known vertex based representation systems are disadvantageous in certain aspects of integrated circuit design applications. Even though the vertex based representation systems are poorly suited to arbitrary angle geometries this is generally not a great concern in integrated circuit design because the industry generally trends towards right angle designs to provide the best photolithographic resolution between horizontal and vertical edges for certain photolithography processes and simplicity because most geometry is machine-generated. Thereby, the main disadvantage in the known vertex based representation systems are speed and size deficiencies. In other words, the known vertex based representation systems use a large amount of memory for intermediate results and unnecessary processing which lead to systems functioning at slow speeds due to the memory manipulation.
One example of a known vertex based geometry engine system is called the "fang" system and was developed in the mid-1980s by Peter Moore at the University of California--Berkeley, no publications of this system are known except for source code and pseudo code developed therefrom. Due to this lack of published documents, a general description of the fang system will follow. FIG. 5 illustrates some examples of fang data structures. The fang data structure includes a fang geometry data structure 520 which includes "sorted" and "reduced" flag bits 522 and 524. Even though the term "merged" is typically used in fang, the term "reduced" is used instead of merged herein, for term consistency. The sorted flag bits 522 indicate whether a vertex list 526 of the vertices is sorted and the reduced flag bit 524 indicate whether the geometry vertices are reduced (whether there are no self-overlaps of geometry).
The example of FIG. 5 illustrates two vertices 530 and 540 in a linked vertex list. The fields for the vertices 530 and 540 include next pointers 532 and 542, which point to the succeeding entry in the linked list, vertex type fields 534 and 544, and x and y values 536, 538 and 546, 548. In the fang system, vertex sorting is performed in a scan line order from left to right and bottom to top. When a new geometry figure is added by reading or collecting the additional geometry, vertices may become out of order because the new vertices are simply appended to the vertex list. Also, when operations such as growing, mirroring, or rotating are performed, the vertices move in different directions which may cause the vertices in the vertex list 526 to become out of order. Accordingly, the vertex list 526 is sorted automatically by the fang system when needed to ensure that the vertices do not become out of order. In the fang system, the vertex list 526 is sorted very frequently and, since the number of operations required in each sort can be expressed as being of order n log.sub.2 n, or "O(n log.sub.2 n)", wherein n is the number of vertices in the list, these operations may use a substantial amount of time.
An important operation in the fang system is reduction. A short description of geometry "depth" will follow as background for the reduction operation. Generally, the geometry depth is the number of overlapping pieces of geometry at a particular point. For instance, a geometry depth of zero indicates that there is a space between geometric figures and no geometry exists at that point. A geometry depth of one indicates that a geometry figure exists at that point and, in general, the value of the geometry depth corresponds to the number of figures overlapping at a point. The geometry depth concept is used in the reduction operation by the fact that a geometry is reduced when the geometry depth is either zero or one throughout the geometry. A geometry will typically be left unreduced after a new geometric figure has been added which overlaps the existing geometry. Therefore, when a new geometric figure is added, the fang system assumes that overlaps have occurred and clears the reduced flag. Similarly, for Grow and Or operations, two geometric figures may overlap and to ensure that the geometry will be reduced, the fang system clears the reduced flag. When an operation requiring reduced geometry is performed, the reduced flag is analyzed and a reduction operation is performed if the reduced flag is not set.
The reduction method of the fang system will be discussed in more detail with reference to FIG. 6. In the fang system, vertices are examined in a scan line order and a temporary list of vertical edges cutting the current scan line is created and maintained during the reduction operation. In the reduction method of the fang system, points are analyzed where a vertex exists in the input geometry or a vertical edge intersects a scan line containing an input vertex. These are the points labeled a-j in FIG. 6. At each of these analyzed points, the geometry depth to the left of the analyzed point (above and below) is known, the vertex (if present) adds offset to the geometry depth to the above-right of the point, and the edge (if present) adds offset to the geometry depths to the right (both above and below) the point. As a result, an output vertex is produced depending on the geometry depth in each quadrant and the edge is added or removed based on the geometry depth .DELTA. above the point (the depth difference between the regions to the upper right and upper left).
A discussion for one example of this reduction method follows for the points a-j of FIG. 6. At point a, a left edge is added to the edge list and an output vertex is created; at point b, a right edge is added to the edge list and an output vertex is created; at point c, a left edge is noticed and no action is performed; at point d, a left edge is added to the edge list and no output vertex is created; at point e, a right edge is noticed and an output vertex is created; at point f, a right edge is added to the edge list and an output vertex is created; at point g, a left edge is removed from the edge list and an output vertex is created; at point h, a left edge is removed from the edge list and no output vertex is created; at point i, a right edge is removed from the edge list and no output vertex is created; and at point j, a right edge is removed from the edge list and an output vertex is created. By these actions, the geometry illustrated in FIG. 6 is reduced to a geometry depth of zero or one throughout. In the fang system, the geometry is frequently reduced and unnecessary reduction operations may be performed which slows the speed of the system. For example, the fang system may unnecessarily reduce the result of an And operation which feeds another And operation. In the worst case, each reduction takes O(n.sup.2) time but in practice, the number of operations is closer to being linear, O(n).
In known vertex based geometry systems, the memory size necessary to process the geometry is generally considered to be the biggest problem. In the fang system for instance, 16 or 20 bytes of data are used to represent each vertex, which requires a large amount of memory. Fang also requires the memory to be simultaneously used for the complete source data and result of each operation, which leads to a large amount of memory being used. Accordingly, the present invention is primarily directed to reducing the amount of memory necessary for performing the routines. Secondarily, and as a by-product of reducing the memory size, the present invention is also directed to increasing the speed for performing these routines.

Vertex based geometry engine system for use in integrated circuit design


A method and apparatus for controlling engine speed during power take-off (PTO) operation. A technique is disclosed which enables accelerator pedal over-ride of PTO operation, wherein PTO operation is resumed when the accelerator pedal induced engine speed value decreases to a preset PTO engine speed. Also, a high-speed governor is employed to limit accelerator pedal-based engine speed during PTO over-ride operation to thereby limit maximum engine speed. In accordance with the invention, the operator of a vehicle can thus accelerate the engine, via actuation of the accelerator pedal, to engine speeds in excess of the preset PTO engine speed without disengaging PTO operation.

Power take-off devices are well known in the heavy-duty, commercial and industrial truck and equipment industries. Power take-off (PTO) devices are used to run various pieces of auxiliary and accessory equipment that maybe attached to such vehicles and equipment, and/or the vehicle and equipment themselves. Typically, the engine associated with the vehicle is used to drive the vehicle and/or the auxiliary equipment when the PTO is enabled and engaged.
One example of a specific use of PTO devices is with refuse collection vehicles. When the PTO is engaged, the operator of the vehicle can compact loose refuse placed therein using the PTO device, which uses engine power to operate a compacting device. Another specific example of the use of PTO devices is with concrete delivery vehicles. The PTO uses the power from the engine to operate the mixing drum as the vehicle transports the concrete to the job site and further to dispense the concrete upon reaching the job site. In either case, the engine used to drive the PTO device may additionally or alternatively be used to drive the vehicle itself. Many other types of vehicles and equipment use PTO devices as well, such as dump trucks, agricultural tractors and construction equipment, to name a few. PTO devices may be used to provide power to such items as pumps, lifts, blowers, and other mechanisms known to those in the commercial and heavy-duty equipment industries.
Typically, the engine speed regulates the speed of the PTO operation while the PTO is engaged. As one specific example of such a system, a pair of operator switches may be used to control PTO operation: 1) a first switch, typically an ON/OFF switch, is used to enable and disable PTO operation; and 2) a second switch, typically a "SET/RESUME" switch, is operable in the SET position to set PTO speed to a first engine speed, and in the RESUME position to set PTO speed to a second engine speed. In PTO operations involving a moving vehicle, the PTO operation is typically limited to calibratable engine speeds, such as 1000 rpm to 1200 rpm. This is due to the operating speed limitations of many PTO devices. In vehicles having a cruise control system, the ON/OFF and SET/RESUME switches used for PTO operation are the same switches provided in known cruise control systems. However, many engines/vehicles operable to drive one or more PTO devices do not include cruise control systems therein, and in the general case the ON/OFF and SET/RESUME switches may be any operator controlled switches.
When PTO operation involves a moving vehicle, many problems may arise involving control of the vehicle speed while the PTO is engaged. For example, it is known in the art for the PTO to disengage when the operator presses a brake or vehicle clutch. U.S. Pat. No. 5,611,751 to Ehrenhardt et al. discloses a PTO control system in which vehicle speed may be controlled by the brake or clutch while the PTO remains engaged.
Another common feature of PTO systems is for the PTO to disengage upon deflection of the accelerator pedal. Alternatively, the engine may be unresponsive to manual manipulation of the accelerator pedal while PTO is engaged. Each of these features are designed primarily to protect the PTO device from being run or engaged at too high of a speed, i.e. in excess of the speed limitations of the PTO device. Unfortunately, these features also cause the PTO to disengage under conditions in which it would be advantageous to have accelerator pedal control of engine speed. Increased engine speeds are not always harmful to the PTO apparatus, such as increasing engine speed for only a short duration, and the PTO device is performing work below its design limitations.
PTO device operators typically bypass the above described PTO control mechanisms by manually disengaging PTO operation using the ON/OFF switch in order to accelerate the engine. However, to resume the PTO set speed, the operator is required to re-engage PTO operation when it is again needed. Thus, known PTO systems suffer the drawback that the operator is required to continuously manually manipulate the PTO ON/OFF switch in order to accelerate the engine. This activity may divert the operator's attention away from the safe operation of the vehicle/engine and other duties the operator might be required to perform.
What is needed, therefore, is a PTO control system that allows engine speed to be easily controlled by accelerator pedal activity while the PTO is engaged, i.e. a PTO control system that allows accelerator pedal over-ride of PTO operation to thereby increase engine speed, yet resumes the previously set PTO speed as the engine speed decreases thereto. The system should be reliable and simple to operate, and should be able to be readily integrated into an existing control system. Finally, the system should allow the vehicle to be operated safely in conjunction with the PTO operation.

Method and apparatus for controlling engine speed during power take-off operation


Upper and lower loopers 2 and 3 are annular loopers. A pump 4 for supplying pressurized air is connected to thread introduction portions 7, which are connected to thread inlets of the loopers through annular conduits 5 and 6 and conduits 5' and 6'. The conduits 5' and 6' are slidable relatively to the conduits 5 and 6, and are connected to thread inlets of the loopers in the threading operation. In this state, the pressurized air is supplied from the pump 4 to the thread introduction portion 7, whereby the thread is transferred by the flow of the air and is fed to an outlet of the annular looper. A connecting portion moving plate 10 for connecting the conduits 5' and 6' is positioned in a disengaged position during the operation of the sewing machine by a stopper 18 and is positioned in an engaged position during a threading operation.

1. Field of the Invention
The present invention relates to a threading device a sewing machine, and particularly to a threading device for automatically passing a thread through a looper of a sewing machine such as a hemstitch overlock machine a double-loop machine, using pressurized gas.
2. Description of the Background Art
As shown in FIG. 11, a hemstitch over-lock machine is an one-needle/three-thread overlock machine including a needle 31a, which is fixed to a needle rod 30 adapted to move substantially vertically in synchronization with a main shaft and is inclined with respect to a cloth feeding direction. The needle 31a penetrates a needle plate 34 and moves substantially vertically. The one-needle/three-thread overlock machine further includes a lower looper 33, which reciprocates under a needle plate 34 along an arc-shaped path crossing a path of the needle 31, and an upper looper 32, which reciprocates along an elliptical path. This elliptical path crosses the path of the lower looper 33 at the side of the needle plate 34 and crosses the path of the needle 31 above the needle plate 34. The one-needle/three-thread overlock machine operates to form a seam in cloth by crossing a needle thread passed through the needle 31, a lower looper thread S2 passed through the lower looper 33 and an upper looper thread S1 passed through the upper looper 32.
In this overlock machine, as shown in FIG. 12, the upper looper 32 is provided at the vicinity of its tip end with a thread outlet, i.e., thread hole 32a through which the upper looper thread S1, guided by an upper looper thread guide 35, is passed and drawn out. Also, as shown in FIG. 12, the lower looper 33 is provided at the vicinity of its tip end with a thread outlet, i.e., thread hole 33a through which the lower looper thread S2 is drawn out. A thread holding portion 33b is provided with a thread groove 33c so as not to disturb the lower looper thread S2, and a thread guide 33d is provided at the rear portion of the looper. The lower looper thread S2 guided by a lower looper thread guide 36 is retained on a lower looper thread guide 37, and then is retained on the thread guide 33d at the rear portion of the looper before being passed through the thread hole 33b at the tip end. A portion of the lower looper thread S2 between the thread guide 33d at the rear of the looper and the thread hole 33b is accommodated and retained in the thread groove 33c.
In the upper and lower loopers 32 and 33 in the prior art, fine work, using tweezers, was required, for passing the thread through the thread hole 32b in the upper looper and the thread hole 33b in the lower looper, engaging the thread on the thread guide 33d at the rear of the looper, and accommodating the lower looper thread S2 in the thread groove 33c. Further, the thread is passed through the looper part in a complicated manner, as shown in FIG. 12, so that one may make a mistake in the sequence for passing the threads (for example, in the hemstitch overlock machine, the sequence is 1: upper looper thread, 2: lower looper thread, 3: needle thread), resulting in problems such as thread breakage at the beginning of the sewing operation and needle breakage. Since the thread groove 33c provided in the thread holding portion 33b for the lower looper thread S2 is open at the front surface, the accommodated lower looper thread S2 may dangle from the thread groove 33c and become entangled with the other thread, resulting in trouble. Since the loopers 32 and 33 are attached to a narrow portion under the throat plate 34, it is difficult to access them with a fingertip or tweezers, and skill is particularly required for passing the thread through the lower looper thread guide 33d of the lower looper 33 and the thread hole 33a in the lower looper 33 which are located at deep positions. An unskilled person cannot correctly pass the threads, or a long time is required for passing the threads, so that the operation must be interrupted for a long time. During the sewing operation, the entanglement of the threads, which results during a restoring operation, e.g., after the thread breakage, may cause thread breakage again.
In order to overcome these disadvantages, a threader or a threading device has been used (disclosed, e.g., in the Japanese Laid-Open Patent Publication No. 1-303194), or such a method has been employed wherein the looper drive is provided with a clutch, and the threading operation is facilitated by laying or inclining the looper by switching the clutch. However, the threading device has disadvantages such as a complicated structure, unstable operation, and skill required for operation. Also it is difficult for an operator to understand the manner for using the threading device, and thus the sewing machine may be broken due to maloperation.
On the other hand, the applicant has proposed a tubular looper shown in FIG. 2, overcoming the above-noted disadvantages, in which the looper has a hollow structure extending from a thread introduction opening to a tip thread outlet (Japanese Patent Application No. 2-310938). In this looper, the thread does not extend through a complicated thread guide as in the prior art shown in FIG. 12, and the threading operation is complicated only by passing the upper and lower looper threads, which are drawn from thread tensioners, through the tubular loopers via the thread guides 35 and 36.
In the structure employing the tubular loopers, the threading paths are simplified to some extent, and the entanglement and breakage of the threads can be prevented. However, the operation for passing the thread through the tubular looper is a manual operation, so that the threading operation is still troublesome.
Accordingly, it is an object of the invention to provide a threading device of a sewing machine, overcoming the above-noted disadvantages deriving from a thread guide having an extremely complicated structure. Another object of the invention is to provide a threading device of a sewing machine and a threading method, in which a thread can be automatically and quickly passed through a looper, using pressurized gas. Still another object of the invention is to provide a threading device of a sewing machine, in which a thread can be passed selectively through a plurality of loopers. Yet another object of the invention is to provide a threading device of a sewing machine, which can prevent malfunction of a main shaft in a threading operation and malfunction of a threading operation during rotation of the main shaft.

Threading machine of a sewing machine and a threading method


A sunshield device for use in a parked vehicle to block sunlight from entering through the vehicle's windows is made of an assemblage of elongated panels. The panels are hingedly interconnected in a vertical array whereby the assemblage can be accordion folded to a compact storage state. The uppermost panel of the assemblage is provided with a suction cup adapted to attach to the window of the vehicle. The suction cup is provided with a mechanism extending through the uppermost panel for achieving release of the suction cup from the window.

1. Field of the Invention
This invention relates to sun blocking devices, and more particularly concerns a folding, retractable sunshield adapted for use in a parked vehicle to block sunlight from entering through the vehicle's windows.
2. Description of the Prior Art
Numerous vehicular sun blocking devices have been disclosed in the prior art. Sunlight entering the vehicle heats the interior and causes degradation of the seats and other components of the interior of the vehicle. Various sunshade devices have been employed to prevent sunlight from entering a parked vehicle, said devices being designed for use either upon the exterior or within the interior of the vehicle. The exterior devices may be comprised of an arcuate semi-transparent member mounted above the upper portion of the front window, thus filtering and shading part of the interior of the vehicle only when the sun is at the higher part of its orbit. Other exterior shade means may comprise a compliant tarp or covering which may cover the windows only or the entire vehicle.
The interior shade devices generally are either curtains, venetian blinds, or roll-up shades which are permanently or semi-permanently mounted upon the windows or window frames of the vehicle. For example, U.S. Pat. No. 3,003,812 to Haugland discloses a multi-pleated panel capable of folding downwardly accordion-style to a compact, horizontally elongated storage state. This design comprises a plurality of moving parts, lending itself to relatively expensive manufacture, and would more than likely require the use of two hands for raising or lowering. It is most preferable to have a shade which may be easily deployed with one hand, particularly for use interiorly of the rear window of the automobile. The other hand may then be used for supporting the user's weight while reaching toward the shade.
U.S. Pat. No. 4,758,042 to Liu discloses a sunshade having a plurality of horizontally disposed accordion folding panels which are held upon the window by means of suction cups. A coiled spring plate mounted upon a handle on the top panel of the shade achieves folding of the shade. This shade design is disposed at the bottom of the window while not in use, thereby obstructing visibility through the lower portion of the window. Another spring-urged shade is disclosed in U.S. Pat. No. 4,932,711 to Goebel. The Goebel device is comprised of a plurality of accordion pleated fabric panels having apertures penetrated by spring urged strings which have upper extremities fixedly associated with a top panel, and lower extremities associated with a shaft urged to rotate by a spiral wound spring. A suction cup is used to maintain the shade in the upright position. A similar device with yet greater complexity is disclosed in U.S. Pat. No. 2,345,106 to Erps. The Erps shade requires an elaborate mechanism which may not be adaptable to existing vehicle doors, and would have limited applicability to front and rear windshields which are generally curved.
U.S. Pat. No. 4,932,710 to Chen discloses a venetian blind device adaptable to the side windows of a vehicle. The venetian blind is not amenable to low cost manufacture, is not easily adaptable to front and rear curved or sloping windshields, and would limit visibility through the upper portion of the window when raised.
Recent developments have been made in shade devices which are manually deployed and removed by the user. U.S. Pat. No. 4,883,304 to Elliot discloses a sun shield constructed of lightweight flexible fabric having vertical stiffening members at the center and lateral extremities. Velcro fasteners are used to maintain the shade in deployed position. U.S. Pat. No. 4,202,396 to Levy discloses a sun shield having a plurality of accordion folded vertical panels, some of which have suction cups at the top which secure the shield to the windshield when deployed. These devices must be manually folded and unfolded, using two hands, and stored elsewhere from the site of use when not in use.
It is accordingly an object of the present invention to provide a conveniently usable sunshade for a vehicle.
It is another object of this invention to provide a sunshade as in the foregoing object which may be easily deployed and retracted with one hand.
It is a further object of the present invention to provide a sunshade of the aforesaid nature which is easily stored in a ready position while not in use.
It is yet another object of this invention to provide a sunshade of the aforesaid nature which may be easily adapted to fit a myriad of automobile windows.
It is still another object of the present invention to provide a sunshade of the aforesaid nature which is durable, compact, easily installed, efficient, and amenable to low cost manufacture.
These and other beneficial objects and advantages will be apparent from the following description.


A thermal expansion valve drives a valve body in a housing through a driving member by a gas pressure of a heat sensitive working fluid sealed in a power element, neighboring the housing, by a diaphragm. The driving member holds a heat ballast at its blind hole opened to the working fluid. A diaphragm has a center opening surrounded by a tubular projection, the diaphragm side end portion of the driving member is inserted in the opening, and a diaphragm catch is fitted on the outer periphery of the projection. The catch, the extended end of the projection and the end of the driving member are airtightly welded to each other.

1. Field of the Invention
This invention relates to a thermal expansion valve and, more particularly, to a thermal expansion valve combined with a thermal bulb.
2. Description of the Related Art
A thermal expansion valve is used together with a compressor, a condenser and an evaporator in a refrigeration apparatus using a refrigerant, and controls the flow rate of the refrigerant flowing into the evaporator in response to the temperature of the refrigerant at an outlet port of the evaporator.
A typical thermal expansion valve comprises: a thermal bulb in which a heat sensitive working fluid is sealed and which is located at the outlet of the evaporator and produces a pressure of a gas of the working fluid in response to the temperature of the refrigerant at the outlet port of the evaporator; a power element which has a diaphragm and which communicates with the thermal bulb by a capillary tube and which activates the diaphragm in response to the pressure of the gas of the working fluid in the thermal bulb; and a valve housing which is adjacent to and combined with the power element, in which two independent refrigerant flow passages are provided, and which holds a valve body to move relative to a valve seat formed in one refrigerant flow passage and which also holds a valve body drive member for transmitting a deflection of the diaphragm of the power element to the valve body to make it sit on and separate from the valve seat in response to the deflection of the diaphragm (that is, the temperature of the refrigerant at the outlet port of the evaporator).
When the conventional thermal expansion valve having such a configuration as described above is used for an air conditioner of an automobile, particularly for a compact car, it is troublesome to install the long and fine capillary tube in a small engine room, and the capillary tube is liable to be damaged under maintenance and repair work in the engine room.
For these reasons, the power element and the thermal bulb are combined with each other in a thermal expansion valve of an automobile air conditioner, and this thermal expansion valve does not use a capillary tube. FIG. 3 shows a longitudinal sectional view of the conventional thermal expansion valve of the automobile air conditioner.
In a valve housing 10 of the thermal expansion valve, a first refrigerant passage 14 and a second refrigerant passage 16 are formed independently from each other, and a valve seat 12 is formed in the first refrigerant passage 14. One end of the first refrigerant passage 14 is connected to an inlet port of an evaporator; an outlet port of the evaporator is connected to the other end of the first refrigerant passage 14 by way of the second refrigerant passage 16, a compressor, a condenser and a reservoir.
A valve body 18 is disposed in the first refrigerant passage 14 and is urged to sit on the valve seat 12 by urging means 17. A power element 20 having a diaphragm 19 is fixed to the valve housing 10 and is disposed adjacent to the second refrigerant passage 16. One chamber 20a partitioned by the diaphragm 19 in the power element 20 is airtightly sealed and contains a heat sensitive working fluid used in a conventional thermal bulb.
A short capillary tube 21 extending from the sealed chamber 20a of the power element 20 is used to degas from or inject the heat sensitive working fluid into the chamber 20a, and the extended end of the tube 21 is airtightly sealed after the completion of degassing and injection.
In another chamber 20b of the power element 20, an extended end of a valve body drive member 22 extending from the valve body 18 through the second refrigerant passage 16 in the valve housing 10 is disposed and abuts the diaphragm 19. The valve body drive member 22 is made of a material having a large heat capacity and transmits heat of a vapor of the refrigerant, flowing out from the outlet port of the evaporator and flowing into the second refrigerant passage 16, to the heat sensitive working fluid in the sealed chamber 20a of the power element 20, so that the working fluid provides a working gas having a pressure in response to a temperature of the vapor of the refrigerant. The other chamber 20b communicates with the second refrigerant passage 16 within the valve housing 10 by way of a peripheral gap of the valve body drive member 22.
Thus, under the influence of the urging force of the urging means 17, the diaphragm 19 of the power element 20 controls the degree of the opening of the valve body 18 relative to the valve seat 12 (that is the flow rate of the liquid refrigerant flowing into the inlet port of the evaporator) in response to the difference between the pressure of the gas of the heat sensitive working fluid in the sealed chamber 20a of the power element 20 and that of the refrigerant vapor in the other chamber 20b or in the outlet port of the evaporator (it is considered that the pressure difference is in proportion to the degree of superheat defined by a difference between the temperature of the refrigerant vapor at the outlet port of the evaporator and that of evaporation of the refrigerant in the evaporator).
This conventional combined type thermal expansion valve can be easily installed in the air conditioner of an automobile, particularly a compact car. But, since the sealed chamber 20a of the power element 20 projects into the space of the engine room, the heat sensitive working fluid in the sealed chamber 20a is influenced by not only the temperature of the refrigerant vapor at the outlet port of the evaporator, transmitted through the valve body drive member 22, but also the temperature of the atmosphere in the engine room.
Therefore, the thermal expansion valve influenced by the atmosphere can not fully work its function.
FIG. 4 shows a thermal expansion valve proposed in U.S. Pat. No. 3,537,645 and improved to eliminate the above disadvantages of the above described conventional thermal expansion valve.
The same components of the improved thermal expansion valve of FIG. 4 as those of the valve of FIG. 3 are indicated by the same reference numerals as those of FIG. 3, and their detailed description will be omitted here.
In the improved conventional thermal expansion valve, an end portion of the valve body drive member 22 located adjacent to the diaphragm 19 is inserted into an opening formed in a center of the diaphragm 19 and is firmly fixed to the central opening of the diaphragm 19. A blind hole 22a is bored in an end surface of the end portion of the valve body drive member 22 to open to the sealed chamber 20a of the power element 20. Since the heat sensitive working fluid in the sealed chamber 20a of the power element 20 can flow into and flow out from the blind hole 22a of the valve body drive member 22, the working fluid functions more in response to the temperature of the refrigerant vapor at the outlet port of the evaporator than in response to the temperature of the atmosphere in the engine room.
The improved conventional thermal expansion valve, however, is too sensitive to and excessively responsive to the temperature of the refrigerant vapor at the outlet port of the evaporator, so that it makes the valve body 18 frequently move between open and closed positions (a "hunting" phenomenon). Such a phenomenon makes the performance of the air conditioner unstable and significantly reduces its efficiency.
Further, in the improved conventional thermal expansion valve shown in FIG. 4, achieving an airtight sealing at the fixing between the central opening of the diaphragm 19 and the corresponding end of the valve body drive member 22 results in a troublesome reduction in the durability of the diaphragm 19.
FIG. 5 shows an enlarged view of the fixing between the central opening of the diaphragm 19 and the corresponding end of the valve body drive member 22. A step is formed in the outer peripheral surface of the end portion of the valve body drive member 22. A diaphragm support member 22b is stacked on the step, and the peripheral portion of the central opening of the diaphragm 19 and a diaphragm catch 22c are placed successively on the diaphragm support member 22b, and an airtight sealing of the central opening of the diaphragm 19 is produced by welding a peripheral edge 22d of the diaphragm catch 22c to the surface of the diaphragm 19.
If the welding is carried out sufficiently to ensure an airtight seal, the inner peripheral edge of the thin diaphragm 19 surrounding the central opening tends to become brittle by heat due to the welding. Consequently, the inner peripheral edge of the diaphragm 19 surrounding the central opening is fatigued and is broken easily after a relatively small number of deflections in operation.
The improved conventional thermal expansion valve as described above is, therefore, still defective in terms of durability, and such thermal expansion valves are not actually used.


A refrigerator has at least one chamber, a temperature adjuster adjusting a temperature inside the chamber, a first temperature sensor approximately sensing the temperature inside the chamber, a second temperature sensor spaced from the first temperature sensor so as to sense the real temperature inside the chamber, and a controller controlling the temperature adjuster according to the temperature sensed by the second temperature sensor when the temperature sensed by the first temperature sensor is within predetermined temperature limits of the chamber and the temperature sensed by the second temperature sensor is not. With this configuration, the temperature inside the chamber is effectively controlled by an accurate and prompt sensing operation. Though one of the first and second temperature sensors is abnormal, it is possible to replace or repair the abnormal temperature sensor, or to control the temperature adjuster by the other normal temperature sensor.

1. Field of the Invention
The present invention relates in general to a refrigerator, and more particularly, to a refrigerator improved in the structure and the control method of a sensor sensing a temperature of a chamber thereof.
2. Description of the Related Art
Generally, a refrigerator is an apparatus which can maintain freshness of food by keeping a chamber at a predetermined cooling temperature, preventing the food from being spoiled. A kimchi refrigerator is also known as a kind of refrigerator, capable of exclusively preserving food such as kimchi, etc. requiring ripening and cooling.
Even if there are various kinds of refrigerators, they have a sensor sensing a temperature of a chamber and a controller controlling them based on the sensed temperature in common, in order to keep the chamber at a predetermined set up temperature.
Descriptions will be made hereinbelow with respect to a kimchi refrigerator equipped with the function of cooling and ripening by way of example.
FIG. 7 is a side sectional view of a conventional kimchi refrigerator. As shown therein, the kimchi refrigerator is comprised of an outer casing 110 forming an outward appearance and an inner casing 120 forming a chamber 111. There is formed a space to be filled with a foaming material between the outer casing 110 and the inner casing 120. Below the chamber 111 is provided a component chamber 113.
In the space to be filled with the foaming material, which is positioned between the outer casing 110 and the inner casing 120, are installed an evaporator pipe 115 and a heater 117, to surround the inner casing 120. In the component chamber 113 are accommodated a compressor 1 14 supplying a refrigerant to an evaporator (not shown), etc.
Further, in the space to be filled with the foaming material, which is positioned between the outer casing 110 and the inner casing 120, is provided a sensor 119 sensing an inner temperature of the chamber 111 and transmitting information of the sensed temperature to a controller (not shown). The temperature sensor 119 is contacting with an outer surface of the inner casing 120 so as to sense the temperature of the chamber 111.
In this conventional kimchi refrigerator, because the temperature sensor is contacting with the outer surface of the inner casing 120 in the space for the foaming material, it is difficult to sense a real temperature inside the chamber 111, and to react promptly to a variation of the inner temperature thereof.
That is, because the temperature sensor senses the temperature of the outer surface of the inner casing to which heat from the evaporator pipe and the heater is directly transferred, a difference between a real temperature inside the chamber and the sensed surface temperature of the inner casing is created. Moreover, where a temperature is changed, for example, by adding new food to the chamber, it takes some time for the changed temperature inside the chamber to affect the temperature of the surface of the inner casing, and therefore, the temperature is neither promptly sensed by the sensor nor controlled by the controller.
In addition, because the sensor is installed in the space for the foaming material between the outer casing and the inner casing, it is impossible to repair or to replace the sensor when the sensor is out of order.


A method and apparatus are provided to clean a paint feed-line (1) of a painting system, line running from at least one paint tank (2, 9) to a paint deposition device (3) and feeding paint in this direction during the operational stages. During cleaning stages between operational stages, a cleaning substance is forced through the feed line (1). An inert gas, for instance nitrogen, is used as the gas for this purpose, and at the end of the cleaning stages the feed line (1) is filled with the inert gas. The gas remains in the feed line (1) until the next operational stage begins.

Methods and apparatus of this kind are used in particular in conjunction with painting systems in the form of robotic painting devices which are widely used for instance in the automotive industry to paint body parts. On the basis of customer behavior, production requirements (such as Just In Time) and the ever increasing number of colors, in particular as regards automobiles, such a painting system frequently must be converted to paints of different colors or to paints of varying properties, illustratively up to 80 changes in paint a day being commonplace. Accordingly modern painting facilities are equipped not only with powerful metering and paint-changing means allowing selection from up to 30 different paints, but also with rinsing and cleaning units precluding undesired residues of the previously used paint from reaching the particular workpiece surface after a change of paint has taken place.
Known methods and apparatus of the initially cited species carry out a cleaning stage between two operational stages involving different paints. This cleaning stage substantially applies to treating a feed line—which moves the paint from a selected supply tank of a color changing or paint changing unit to a deposition device (atomizing unit or the like)—by means of a cleaning substance typically in liquid form flowing through said feed line. Said cleaning substance is forced by compressed air through the feed line either in the direction of paint flow (German patent document 20 43 789 C3) or in the opposite direction (German patent document 91 10 650 U1). In both cases the cleaning substance must be removed from the feed line before the next operational stage begins. The cleaning effect may be enhanced by moving to-and-fro a ball or another body—generally called "pig"—in the feed line (European patent document 0 888 825 A2).
A problem arises with such methods and apparatus for cleaning feedlines in that the contemporary liquid paints and especially their hardeners are exceedingly sensitive to oxygen. Even minute paint residues react under ambient atmosphere, forming solid clumps or chunks which, while being small, nevertheless are visible on a smooth, painted surface and render the pertinent workpiece nearly useless. Such clumps being inevitable on account of the compressed air used in cleaning, it must be reliably removed from the feed lines before the new paint reaches the deposition unit, provided that, on one hand, comparatively large quantities of cleaning substance be used. On the other hand, a cleaning substance free of oxygen or air must remain in the feed line during the entire time interval between two operational stages using different paints in order to preclude formation during said time interval even of the tiniest air bubbles and hence paint clumps. As a result, at the beginning of new operational stage, i.e. at the beginning of a new painting stage, not only the cleaning substance per se, but furthermore a given minimum quantity of follow-up paint must be expelled from the deposition device and be transferred into a collecting container before the actual painting may start, in order to reliably preclude any residual quantities of the cleaning substances B which usually contain a solvent B from reaching the workpiece surface to be painted.
The quantities of paint and cleaning substance that are lost in this manner during each cleaning stage are considerable and amount to substantial costs. Also the paint and the cleaning substance must be removed as special wastes, entailing further costs and ecological loads. These factors apply regardless of the cleaning procedure being enhanced using a so-called pig or not.

Method of cleaning a paint feed line of a painting system


The ink detecting device gives advance warning of the end of the ink in a reservoir or cartridge feeding an ink-jet thermal print head. The device comprises a pair of electrodes that are immersed in a spongy, ink-soaked body contained in the reservoir, and are arranged in a region adjacent to the feed duct at which the spongy body has a 30% to 100% higher capillarity than in remote regions. The electrodes are connected to a bridge circuit which measures the electrical resistance of the ink between the two electrodes.

The present invention relates to an ink detector for a liquid-ink printing element, and more particularly to an ink detector for indicating when a minimum amount of ink remains in the reservoir which feeds an ink-jet print head.
In thermal ink-jet heads, which are well known in the art, the nozzles, the spray chambers and the heating elements are formed on a multi-layer silicon-based chip manufactured by the known processes of vacuum deposition employed in the manufacture of integrated circuits.
In the case of multiple-nozzle heads, the various spray chambers are connected in parallel to a common collecting channel. This is connected in turn through a feed duct to a reservoir or replaceable ink cartridge.
An example of a multiple-nozzle thermal ink-jet print head is described in U.S. Pat. No. 4,812,859, in which a multi-layer silicon-based chip containing the spray chambers, the heating elements and the nozzles is attached directly to the ink reservoir. The reservoir contains a sponge impregnated with ink and is mounted on the carriage of a printer.
The use of sponges to reduce and stabilise the hydrostatic head in the outlet duct of an ink reservoir is also known from U.S. Pat. No. 4,630,758, in which it is shown that the sponge causes a pressure drop in the reservoir outlet duct by capillary action.
In European Patent Application published under No. 408,241 on 16 Jan. 1991, a thermal ink-jet print head is described in which the ink reservoir is of the replaceable cartridge type and is inserted on a support to which is fixed the multi-layer silicon-based chip containing the spray chambers, the heating elements and the nozzles. The cartridge contains an ink-soaked sponge and is able to form a fluid connection with the support to supply ink to the multi-layer chip.
However, the patents cited above make no mention of possible ways of monitoring the amount of ink remaining in the cartridge.
A number of devices for monitoring the amount of ink contained in a reservoir feeding a print head are known from U.S. Pat. Nos. 4,183,029, 4,196,625 and 4,202,267.
These patents relate in particular to feed reservoirs that are completely filled with ink and do not use a sponge. Electrodes are arranged in pairs on the floor of the reservoir next to the outlet duct, or, as in U.S. Pat. No. 4,183,029, directly inside the feed duct between the reservoir and the print head.
Measuring circuits connected to the electrodes measure the variation in the resistance of the ink between each pair of electrodes, and this corresponds to the decrease in the amount of ink remaining in the reservoir. When the electrodes become uncovered by the ink, the measuring circuit indicates that the ink has run out.
In these devices, the resistance of the ink varies slowly as the ink in the reservoir is used, and suddenly climbs to a very high level when the ink is finished.
It is therefore very difficult to determine when one has arrived at a minimum amount of ink before it is exhausted, so as to replace the cartridge or reservoir.
What is more, these devices cannot be adapted to reservoirs and/or cartridges containing an ink-soaked sponge, even if high-quality sponges are used such as those with a three-dimensional cross-linked structure of melamine-formaldehyde resin, as described for example in U.S. Pat. No. 4,929,969.
In this case, the balance between the capillarity of the nozzles and the capillarity of the terminal area of the sponge, close to the floor of the container, causes print deterioration or stoppage before the sensors on the floor of the container or in the outlet duct detect a significant rise in the increase of the resistance of the ink.
There is also known, from European Patent Application published under No. 370,765, another kind of end-of-ink detector formed by two electrodes placed in the ink feed duct leading to the spray chambers of a thermal ink-jet print head. One electrode is sited close to the spray chamber, while the other electrode is arranged upstream, towards the reservoir. A detector circuit indicates variations in the resistance of the ink between the two electrodes.
This type of detector, too, when applied to a reservoir containing an ink-soaked sponge, has the same disadvantages as indicated above.

Ink detecting device for a liquid-ink printing element


A generator of time-variable magnetic fields of a magnetic resonance apparatus, said apparatus having an examination space for imaging of at least one area of an examination subject to be examined, incorporates the following features:                the conductors of a gradient coil arrangement of the generator extent over an essentially disk-shaped area,        the area includes at least one sub-area which is free from conductors of the gradient coil arrangement and within which are arranged conductors of a high-frequency antenna of the generator, and        a field backflow space, which is available inter alia for fields of the high-frequency antenna, extends away from the examination space, starting from the sub-area.

Magnetic resonance technology is a known technology, the objectives of which include obtaining images of the interior of the examination subject's body. Thus in a magnetic resonance apparatus, rapidly switched magnetic gradient fields that are generated by a gradient coil system are superimposed on a static basic magnetic field which is generated by a basic field magnet. The magnetic resonance apparatus also includes a high-frequency antenna, which beams high-frequency signals into the examination subject in order to trigger magnetic resonance signals, and picks up the triggered magnetic resonance signals on the basis of which magnetic resonance images are produced.

Generator for generating time-variable magnetic fields and magnetic resonance device


A display apparatus which can display an image at a proper luminance corresponding to a video signal irrespective of a temperature-related change or a change with the passage of time. The display apparatus has: a current source for generating a reference current; and a reference transistor having an input terminal for a power voltage, an output terminal to which the current source is connected, and a control terminal connected to the output terminal and having almost the same electrical characteristics as those of a driving transistor for supplying a drive current to a light emitting device serving as a pixel. The driving transistor is driven by a voltage (reference control voltage) on the control terminal of the reference transistor. The loss of electric power can be suppressed by the driving method of this apparatus.

1. Field of the Invention
The invention relates to a display apparatus having an active matrix driving type display panel.
2. Description of Related Art
Recently, an electroluminescence display apparatus (hereinafter, referred to as an EL display apparatus) is drawing attention, in which a display panel using an organic electroluminescence device (hereinafter, referred to as an EL device) is mounted as a light emitting device including pixels. As the driving scheme for the display panel by the EL display apparatus, an active driving type system is known.
FIG. 1 is a diagram schematically showing the construction of an active driving type EL display apparatus.
As shown in FIG. 1, the EL display apparatus is constituted by a display panel 10 and a driving apparatus 100 for driving the display panel 10 with a video signal.
The following elements are formed on the display panel 10: a common ground electrode 16; a common power electrode 17; scanning lines (scanning electrodes) A1 to An serving as n horizontal scanning lines of one screen; and m data lines (data electrodes) D1 to Dm arranged to cross the scanning lines, respectively. Active driving type EL units E1,1 to En,m functioning as pixels are formed in the crossing portions of the scanning lines A1 to An and the data lines D1 to Dm, respectively. A power voltage VA to drive the EL units E is applied to the common power electrode 17. The common ground electrode 16 is connected to the ground.
FIG. 2 is a diagram showing an example of the internal construction of one EL unit E formed in the crossing portion of one scanning line A and one data line D.
In FIG. 2, the scanning line A is connected to the gate of an FET (Field Effect Transistor) 11 for selecting the scanning line and the data line D is connected to the drain of the FET 11. The gate of an FET 12 for light emission driving is connected to the source of the FET 11. The power voltage VA is applied to the source of the FET 12 via the common power electrode 17. A capacitor 13 is connected between the gate and the source of the FET 12. Further, an anode terminal of an EL device 15 is connected to a drain of the FET 12. A cathode terminal of the EL device 15 is connected to the ground via the common ground electrode 16.
The driving apparatus 100 sequentially applies scanning pulses to the scanning lines A1 to An of the display panel 10 in an alternative way. The driving apparatus 100 further generates pixel data voltages DP1 to DPm corresponding to the horizontal scanning lines based on the incoming video signal and applies those voltages to the data lines D1 to Dm in synchronism with the timing of the application of the scanning pulses, respectively. In this process, each EL unit connected to the scanning line A to which the scanning pulse has been applied becomes a writing target of the pixel data. The FET 11 in the EL unit E serving as a writing target of the pixel data turns on in response to the scanning pulse and applies the pixel data voltage DP supplied via the data line D to the gate of the FET 12 and to the capacitor 13, respectively. When the pixel data voltage DP is low, the FET 12 supplies a predetermined light emission drive current Id which is generated based on the voltage VA to the EL device 15. The EL device 15 emits light at a predetermined luminance in accordance with the light emission drive current Id.
When the gate-source voltage/output current characteristic of the FET 11 is shifted due to a temperature-related change, a change with the passage of time, or the like, even with a fixed gate source voltage VGs(=the power voltage VA−a gate voltage G) a fluctuation of the output current, that is, the light emission drive current Id occurs. This occurrence results in the fluctuation of the luminance of the EL device 15. The power voltage VA has previously been set to a lightly high voltage in consideration of the increased amount of a forward voltage due to the temperature-related change, change with the passage of time, or the like in the EL device 15. Therefor, the loss of electric power increases at the initial stage or at a standard state.

Display apparatus with active matrix type display panel


An arrangement for controlling a work vehicle includes a power source, and a hydraulic circuit including a pump driven by the power source, at least one hydraulic actuator arranged in fluid connection with the pump via a first conduit, a variable displacement hydraulic motor unit arranged in fluid connection with the actuator and downstream the actuator via a second conduit. The variable displacement hydraulic motor unit is arranged for controlling movement of the actuator.

The present invention relates to an arrangement for controlling a work vehicle, comprising a power source, and a hydraulic circuit comprising a pump driven by the power source, at least one hydraulic actuator arranged in fluid connection with the pump via a first conduit, and a variable displacement hydraulic motor unit arranged in fluid connection with the actuator and downstream the actuator via a second conduit. The invention is also related to a method for controlling a work vehicle.
The pump is normally operatively driven by an internal combustion engine arranged for propelling the work vehicle.
The term work vehicle comprises different types of material handling vehicles like construction machines, such as a wheel loader, a backhoe loader, a motor grader and an excavator. The invention will be described below in a case in which it is applied in a wheel loader. This is to be regarded only as an example of a preferred application.
Said actuator may be a linear actuator in the form of a hydraulic cylinder. A wheel loader comprises several such hydraulic cylinders in order to perform certain work functions. A first pair of hydraulic cylinders is arranged for turning (steering) the wheel loader. A second pair of hydraulic cylinders is arranged for lifting a load arm unit and a further hydraulic cylinder is arranged on the load arm unit for tilting an implement, for example a bucket or forks, arranged on the load arm unit.
Conventional hydraulic systems normally comprise a directional valve arranged upstream of the hydraulic actuator for controlling the supply of fluid from the pump to the actuator and thereby also the movement of the actuator. The directional valve is adjusted in a continuously variable way according to a desired movement of the implement. Thus, the fluid flow from the pump is throttled to a greater or lesser extent in order to achieve the desired movement.
Prior art hydraulic systems have some energy losses during operation. Some of these energy losses are described below.
For example, when a function is actuated, the load is brought to a certain speed (for example during steering of the vehicle). Braking the load to a lower speed or to a stop is done by throttling the fluid. The kinetic energy from the load is thereby transmitted to the fluid via the valve outlet.
Further, there is a risk of vehicle instability in certain situations. For example, when the vehicle is steered by means of the associated actuators, the vehicle may bounce sideways.
Further, during a lifting operation of the implement, it is first raised to a certain level by supplying the associated actuators with hydraulic energy. This energy is transferred to potential energy when the implement is in the raised position. This energy is throttled via said valve when the implement is lowered. The loss of energy is particularly high when a load is lowered (for example when a pallet is lowered from a rack).
Further, during a tilting operation of the implement (in the form of a bucket) , it is first tilted upwards to a certain level by supplying the associated actuator with hydraulic energy. This energy is transferred to potential energy when the implement is in the raised position. This energy is throttled via said valve when the implement is tilted downwards again.
Further, when the implement is lowered and when the implement (bucket) is emptied, respectively, the gravity acts as a downward force. The pump continue to pump also in this situation, when only the gravity force in principle could be used to move the implement.
It is known to use a so-called Load Sensing hydraulic system (LS system) in the work vehicle. The LS system comprises means for sensing a load pressure subjected to the actuator during operation. More specifically, the load is sensed and the output pressure of the pump is controlled so that it exceeds the load pressure existing in the actuator by a predetermined differential. More specifically, the pressure (an LS signal) from the actuator for the load may be sensed via a shuttle valve and via an activated control valve unit associated with the actuator for the load. The pump then delivers a hydraulic fluid flow to the actuator, the level of which depends on the extent to which the activated control valve unit is operated.
The LS system generally has a relatively high efficiency. However, the LS-system has some energy losses. Some of these energy losses are described below.
The pump in a conventional load-sensing system works for keeping a constant pressure drop over the directional valve. The flow is determined by the opening area of the valve. The magnitude of the pressure drop depends on the system design and valve type, but is normally 10-25 Bar. A wheel loader is often operated with a low number of revolutions of the engine and several work functions are performed at the same time. This leads to that the pump is unable to saturate the pressure of the valves when they are fully opened, which in turn leads to lower pressure drops.
When several work functions are actuated at the same time in a LS-system with a common pump, the pump needs to generate a pressure level that can handle the highest actuator pressure. This means that the valves controlling the further actuator(s) (functions), will get very high pressure drop, which will be throttled away in the associated valve.
Oil resources are becoming more scarce in the world, which increases the prices of oil-based fuels. The efficiency of vehicles requiring oil-based fuels therefore becomes more important in the future. For work vehicles, there is a problem of energy losses in the hydraulic systems.
In U.S. Pat. No. 6,789,387, a hydraulic system for recovering energy in a work vehicle is disclosed. The system is arranged to recover energy during an overrunning load condition, i.e when a hydraulic cylinder is retracted due to its own weight after it has been extended to lift a load. An overrunning load condition is sensed and a valve is thereafter actuated so that a fluid from the cylinder is directed to a hydraulic motor for producing a torque output. One disadvantage is that the system is limited to recover energy only during said overrunning condition.
In U.S. Pat. No. 6,725,581, a hydraulic system for recovering energy in a work vehicle is disclosed. The system comprises several hydraulic actuators for performing different work functions. Several switches are arranged for guiding a return oil from one of said hydraulic actuators depending on a detected back pressure of the actuators. A pump motor is rotatably driven by the return oil from the selected hydraulic actuator. A dynamo-electric generator is coupled to the pump motor for generating electric power from the rotary force of the pump motor. One disadvantage is that the system is limited to recover energy for only one work function at the same time.
It is desirable to create conditions for a system that is more energy-efficient than previously known systems and solves or at least relieves some of the problems discussed above.
According to an aspect of the present invention, the means for controlling movement of the actuator is formed by the variable displacement hydraulic motor unit. Thus, the fluid is pumped in the hydraulic circuit from the pump to the actuator via the first conduit and in return from the actuator to the hydraulic motor unit via the second conduit and further to a reservoir. The wording "movement of the actuator" refers in this case to the speed of the actuator.
Thus, the hydraulic motor unit, which is arranged downstream of the actuator, is used for controlling the movement of the actuator. Hence, no directional control valve is required upstream of the actuator for controlling the actuator and the abovementioned problems with throttling losses are eliminated. Further, the variable displacement hydraulic motor unit is preferably the only means for controlling movement of the actuator.
Thus, the means for controlling movement of the actuator is formed by the variable displacement hydraulic motor unit in combination with that the fluid connection through the first conduit from the pump to the actuator is free from actuator movement controlling throttling means.
According to an aspect of the invention, the fluid is directly supplied from the pump to the actuator. In other words, the fluid connection through the first conduit from the pump to the actuator is free from throttling means, i.e the first conduit is fully open and the fluid flow is supplied to the actuator is a non-manipulated, non- throttled manner.
According to an aspect of the invention, the arrangement comprises means for electrically controlling the displacement of the variable displacement motor unit. Said electrical control means is preferably formed by a controller.
The control of the displacement may be done in response to receiving a work function signal from an operator maneuverable control lever. The signal from the operator lever may further be manipulated in the controller. For example, ramps for initiating and terminating an actuator movement, respectively, may be stored in a memory and used for displacement control. The displacement of the motor unit may also be regulated according to a sensed operating parameter of the vehicle, such as the number of revolutions of the power source. The movement of the actuator may thereby be controlled in an effective and smooth way.
According to a further aspect of the invention, the motor unit is arranged for a rotation connection to the power source in order to transmit energy to the power source.
By virtue of this arrangement, any excess hydraulic energy supplied by the pump is recovered back to the power source via the hydraulic motor unit. Excess hydraulic energy is supplied by the pump when it is working at an unnecessary high pressure level (which is the case for example in a system with a constant pump pressure).
Further, a potential energy achieved when the implement is raised to a raised position is recovered by the motor unit and transmitted to the power source when the implement is lowered. The recovery of energy is particularly high when a load is lowered (for example when a pallet is lowered from a rack).
Since the hydraulic motor unit is connected to the power source such that it transmits energy from the fluid flow to the power source, the problem of energy losses in the conventional directional valve is solved and any excess hydraulic energy provided by the pump may be recovered in the hydraulic motor unit.
According to a further aspect of the invention, the arrangement comprises a set of on/off valves arranged on the first and second conduit for actuating the associated hydraulic actuator. Thus, these on/off valves are adapted to be arranged in one of two end positions; a first position, in which the fluid connection is fully open and a second position, in which the fluid connection is fully closed. The above mentioned problem with pressure drop is thereby substantially solved. The movement of the on/off valve from one end position to the other end position may be controlled in a continuous way so that the transition is not too abrupt. For example, the first and last part of the movement distance may comprise a ramp for a smooth operation.
In the case of a hydraulic cylinder for controlling a work function, there are two input conduits to and two output conduits from the cylinder. A first input conduit is connected to a piston side and a first output conduit is connected to a piston rod side. A second input conduit is connected to the piston rod side and a second output conduit is connected to the piston side. An on/off valve is arranged on each of these four input/output conduits and by simultaneously open the on/off valves at the first conduits or the second conduits, the cylinder can be moved in different directions by means of the pressurized fluid from the pump. Preferably, the controller is arranged for electrically controlling the on/off valves based on operator command signals.
According to a further aspect of the invention, the arrangement comprises means for sensing a load pressure subjected to the actuator during operation. By using the load-sensing system in the control arrangement according to the invention, several energy losses associated with hydraulic systems with conventional control of the actuator (via a directional valve upstream of the actuator) may be relieved.
According to a further aspect of the invention, the arrangement comprises a plurality of hydraulic actuators for performing a plurality of work functions, and that one variable displacement motor unit is arranged for controlling each work function. Thus, each work function, like steering, lift and tilt is connected to a separate motor unit. In this way, the movement of each actuator may be controlled independently from the other actuators. The recovery of energy is especially efficient when several work functions are used simultaneously. The pump supplies a sufficiently high pressure for the highest loaded work function and all excess energy is recovered via the motor units.
According to a further aspect of the invention, the power source is connected in such a way to at least one further energy using system/component in the vehicle that energy recovered by the motor unit may be transmitted to it. For example, when the implement is lowered, the energy recovered by the motor unit is larger than the -energy supplied by the pump due to the fact that the motor unit will receive the potential energy of the load arm unit and the load. This excess energy can be used by the power source to drive for example the vehicle driveline and/or further vehicle systems like the service brake system and/or components like fans and generators etc.
The term "driveline" is in the following referred to as the arrangement downstream the engine for transmitting power from the engine to the vehicle ground engaging members (wheels or tracks).
It is also desirable to achieve a control method that is more energy-efficient than previously known methods and solves or at least relieves some of the problems discussed above.
A method according to An aspect of the present invention is also disclosed.
Further advantageous embodiments and further advantages of the invention emerge from the detailed description below.

Arrangement and a method for controlling a work vehicle


An apparatus cooperation system including first and second apparatuses connected via a network to share a function, the first apparatus including a first counting unit counting a number of the output objects output by the first output unit based on a first counting rule, the second apparatus including a second counting unit counting a number of the output objects output by the second output unit based on a second counting rule. Further, when an output condition to output the image data by the first apparatus and the second apparatus is accepted, the first counting unit counts a total number of the output objects output by the first output unit and the second output unit based on the first counting rule.

1. Field of the Invention
The present invention generally relates to a apparatus cooperation system where plural apparatuses connected to each other via a network share and provide functions of the apparatuses among the apparatuses.
2. Description of the Related Art
The apparatuses such as copiers are generally provided to many businesses as clients on lease or rental basis. This is because those apparatuses generally require maintenance services. In this case, for example, the client pays not only a lease charge but also the other charge in accordance with the lease contract to a leasing company. To determine the other charge, there have been used a counter method and a toner kit method.
In the counter method, for example, the client pays an amount corresponding to a basic charge and a charge determined by the product of the number of printed pages by contracted unit price as a monthly charge.
Further, in the counter method, the client may usually have to pay a cost for consumable supplies (e.g., toner and other parts) and a maintenance and inspection charge including the costs of exchanging parts and adjustment of the apparatus.
On the other hand, in the toner kit method, the client purchases a toner kit. By doing this, the leasing company provides the maintenance service. In this method, the client may use the apparatus until the toner is empty by paying a fixed charge of the toner kit.
It is not possible to determine which of the methods is advantageous because it depends on the frequency of use of the client. However, if the apparatus is not used very frequently, the toner kit method may be recommended.
In the counter method, the charge depends on the (printed) pages. Therefore, it is necessary for the apparatus using the counter to count the number of the printed pages. Further, it is usually unknown whether the client makes a contract based on the counter method or the toner kit method when the apparatus is shipped from the factory. Therefore, almost all MFPs (apparatuses) include a function for counting the printed pages.
FIG. 1 schematically illustrates examples of billings when a user Q uses an apparatus (MFP 1) employing the toner kit method and an apparatus (MFP 2) employing the counter method. Namely, the MFP 1 is used under a billing contract based on the toner kit method, and the MFP 2 is used under a billing contract based on the counter method.
In case the user uses the MFP 1 to print, for example, 10 pages, due to the toner kit method, the MFP 1 does not have to count the number of printed pages. On the other hand, in case the user uses the MFP 2 to print 10 pages, due to the counter method, the MFP 2 counts the number of printed pages and the counted value is stored in the MFP 2.
On the other hand, there has been known a processing scheme in which plural apparatuses connected to each other via a network cooperate each other to perform a job (see, for example, Japanese Laid-open Patent Publication No. 2010-074431). This processing scheme may be called "apparatus cooperation".
The "apparatus cooperation" herein refers to a scheme is which, for example, plural apparatus cooperate with each other by sharing and providing a function necessary for (executing) a job including a series of processes from input to output.
FIG. 2 illustrates an example how a job is executed in the processing scheme called "apparatus cooperation". In FIG. 2, the MFP 1 and the MFP 2 are the same as those in FIG. 1. The user 2 is intended to print plural copies of image data. To that end, the user Q may use the MFP 1 only.
However, if the user Q uses not only the MFP 1 but also MFP 2 so that the print job is shared by the MFP 1 and the MFP 2, the user Q may finish printing faster. So as to print by sharing between the MFP 1 and the MFP 2, the user Q may operate the MFP 1 to scan the draft by the scanner of the MFP 1 and send the scanned image data along with the printing conditions to the MFP 2.

Apparatus cooperation system, image forming apparatus, and function providing method


A framework for a display booth includes at least one base, at least one post, at least one beam and a connector. The post is adapted to be releasably attached to the base and to extend vertically upward from the base when attached thereto. The post includes at least two panels pivotally secured together. The beam is adapted to be releasably attached to the post and includes at least two panels pivotally secured together. The connector is adapted to be releasably attached to both the post and the beam. The connector is adapted to support the beam on the post when the connector is connected to both the post and the beam. The post and the beam may be folded to a folded orientation to ease transportation and storage of the framework when it is not in use.

In the past, truss systems have often been used to construct display booths, The truss systems use vertical posts to which are mounted one or more horizontal beams. Typically, the posts are placed at the corners of the floor space that has been allotted to the particular vendor who is using the booth. The posts extend vertically upward a preset distance, such as about eight feet or thereabouts. At the top of the posts, horizontal beams are supported that extend between each of the posts. Banners, signs, or other display material may be hung from the horizontal beams.
The prior truss systems have suffered from several disadvantages. First, the trusses are usually constructed in such a fashion that they are relatively heavy items. This makes transporting them difficult, as well as manipulating them during construction and deconstruction of the booth. Second, the trusses and other components used to construct the booth are often long, such as eight feet or more. This also makes the transportation, as well as the storage, of these components difficult. Further, prior trade show booth frames have often required the use of separate fasteners to secure together all of the components of the frame. This increases the time and labor necessary to construct and deconstruct the booth framework.
Therefore, there is a need in the art for a trade show display booth framework that overcomes these and other difficulties encountered by the conventional systems and booths.


A three-dimensional photonic crystal includes a structure that includes first, second, third, and fourth layers in this order. The structure of each layer includes a flat surface as one end surface, and first, second, and third structural portions. The first structural portion has a first width along the flat surface and a first height from the flat surface. The second structural portion has a second width larger than the first width and a second height larger than the first height. The third structural portion has a width and a height that continuously or stepwise change in the extending direction of the structure. The flat surface at the structural portion of one of two adjacent layers in the first layer to the fourth layer contacts a surface opposite to the flat surface at the second structural portion of the other of the two adjacent layers.

1. Field of the Invention
The present invention relates to a three-dimensional photonic crystal having a three-dimensional periodic refractive-index structure, and a manufacturing method thereof.
2. Description of the Related Art
Yablonovitch, Physical Review Letters, Vol. 58, p. 2059, 1987 proposes a concept of controlling the electromagnetic wave's characteristic, such as a transmission and a reflection, through periodically arranged structures as large as or smaller than a wavelength. This structure is known as a photonic crystal, and implements an optical element having a reflectance of 100% without a loss of the light in a predetermined wavelength region.
The operation that makes the reflectance 100% in the predetermined wavelength region is referred to as a photonic band gap (operation), in comparison with the energy gap of the semiconductor.
Furthermore, A three-dimensional fine periodic structure provides a photonic band gap to the incident light from all directions. This is also referred to as a complete photonic band gap (operation).
With the complete photonic band gap, a variety of applications including a control of a spontaneous emission in a light-emitting element are available, and a new functional device that does not conventionally exist can be implemented. Therefore, a functional device configured to implement the complete photonic band gap in a wider wavelength region.
Conventionally, U.S. Pat. Nos. 5,335,240, 5,440,421, and 6,597,851 propose some structures each having a complete photonic band gap operation.
U.S. Pat. No. 5,335,240 discloses a woodpile structure that has a stack of a plurality of layers, each of which arranges a plurality of columnar structures in parallel having a constant sectional shape. In the plural layers, directions of columnar structures alternately differ by 90°.
U.S. Pat. No. 5,440,421 discloses a structure that arranges and partially overlaps a plurality of parallel columnar structures in a stacking direction, and has a plurality of holes that extend in the stacking direction.
U.S. Pat. No. 6,597,851 discloses a stacked structure that arranges a plurality of layers while shifting them by a length that is ⅓ as long as a fundamental period, each layer having a plurality of hexagonal columnar structures that extend in the stacking direction on a flat part that has a plurality of holes.
The woodpile structure proposed in U.S. Pat. No. 5,335,240 has an advantage of a simple structure and an easy manufacture because four layers constitute one period.
Since the photonic band gap of the woodpile is narrower than that of the inverse opal, it is difficult to realize a device (such as a waveguide and a wavelength selective filter) which can operate in a wide operational band. However, the inverse opal that can provide the device that can operate in the wide operational band is hard to manufacture by the conventional semiconductor process.
In addition, the structure proposed in U.S. Pat. No. 5,440,421 also has the complete photonic band gap, but requires a plurality of very deep holes, and is hard to manufacture.
Moreover, the structure proposed in U.S. Pat. No. 6,597,851 has smaller anisotropy and a comparatively wider photonic band gap width than the woodpile structure. However, it is difficult to manufacture because six layers constitute one period, and require an extremely high alignment precision among these layers.

Three-dimensional photonic crystal and manufacturing method thereof


Processes are provided for contacting at least one Cn alcohol equivalent having n carbon atoms and at least one Cn+1 alcohol equivalent having (n+1) carbon atoms with a Guerbet catalyst to form a product composition comprising a product compound having the structure:

Branched aldehydes and alcohols have a number of significant industrial uses. Isobutyraldehyde, for example, is useful as a precursor to isobutanol, isobutyric acid and coalescent molecules, all of which have a variety of uses. Isobutanol is used, for example, in a number of fuels, coatings, solvents and cleaners, as well as in making isobutyl acetate and p-xylene, and as an intermediate in making ester solvents and plasticizers. Higher molecular weight aldehydes and alcohols such as 2-methylbutyraldehyde, 2-methyl-1-butanol, 2-ethylpentanal, and 2-ethyl-1-pentanol are useful either as precursors in the flavors and fragrances industry, as components in personal care product formulations, or as precursors to low volatility plasticizers and paint coalescents.
Isobutyraldehyde is commonly made through the hydroformylation of propylene. As such, isobutyraldehyde, and therefore its derivative isobutanol, is subject to risks regarding changes in price or availability of propylene. Selective hydroformylation of butene and hexene to produce 2-methylbutyraldehyde and 2-ethylpentanal, respectively, remains a synthetic chemistry challenge. Identification of alternate routes to these compounds remains a priority, and identification of routes that would avoid dependency on olefin availability would be useful. Conversion of simple low cost alcohols such as methanol, ethanol and propanol to these value added aldehydes and alcohols are therefore of interest.

Conversion of alcohols to longer chain aldehydes or alcohols

Abstract: wherein:        C is a carbon atom;        H is a hydrogen atom;        Q is an alcohol or aldehyde group having one carbon;        R is a linear alkyl group having n carbon atoms; and        T is an alkyl group having (n−1) carbon atoms, except that when n=1, T is methyl.


An arc tube for a discharge bulb is provided for use in a vehicular lighting system. The arc tube includes a closed glass bulb that is pinch-sealed at opposite ends. Inner ends of a first electrode and a second electrode extend into the closed glass bulbs from the ends of the closed glass bulb. The atmosphere inside the closed glass bulb includes a starting rare gas, a primary light-emitting metal halide, and optionally, a buffer metal halide. The distance between the inner ends of the electrodes is between about 0.3 and 1.8, and the inner diameter of the closed glass bulb at a middle portion is between about 1.5 mm and 2.7 mm. Accordingly, a stable discharge is produced using between 15 W and 30 W of power.

1. Field of the Invention
The present invention relates to an arc tube for a discharge lamp unit having a closed glass bulb in which a pair of electrodes are disposed, and a pinch seal on both sides of the closed glass bulb. In particular, the present invention relates to a mercury-free arc tube for a low-voltage discharge lamp unit having a closed glass bulb filled with a primary light-emitting metal halide, an optional buffer metal halide, and a starting rare gas.
2. Background of the Related Art
FIG. 3 illustrates a related art discharge bulb used in a discharge lamp unit as a light source of vehicular lamps. The related art discharge bulb includes an arc tube 2 containing a closed glass bulb 2a (or a light emitting portion) formed integrally with a resin insulating plug body 1. The rear end of the arc tube 2 is supported by a metal support 8 that is fixed to the insulating plug body 1, and the front end of the arc tube 2 is supported by a metal lead support 9 that extends from the insulating plug body 1 and serves as a current path.
The arc tube 2 is pinch-sealed at both ends by pinch seals 2b. The closed glass bulb 2a has opposing electrodes 3 extending into the ends of the closed glass bulb of the arc tube 2, which is filled with a metal halide as a primary light-emitting substance, mercury as a buffer gas, and a rare gas as a starting gas.
Mercury in the arc tube is the buffer for maintaining a prescribed tube voltage and buffering (i.e., reducing electron collision against the electrodes) to reduce electrode damage. Mercury is also an auxiliary light-emitting substance for generating white light.
In the related art discharge bulb, light is emitted from an arc discharge created between the electrodes 3. Since arc tubes produce more light and have a longer service life than incandescent lamps, they are being increasingly used as a light source of headlights or fog lights.
In the related art discharge bulb illustrated in FIG. 3, a lead wire 4 is located at an end of the pinch seal 2b. A pinch-sealed molybdenum foil 5 is connected between a lead wire 4 and a tungsten electrode 3. The arc tube 2 is integrally welded to a glass shroud 6 that provides ultraviolet shielding and creates a closed space that includes the foregoing elements. The glass shroud 6 blocks ultraviolet rays in a wavelength range harmful to human body from being emitted by the arc tube 2, and keeps the glass bulb 2a at a high temperature.
However, the foregoing related art discharge bulb has various problems and disadvantages. Because the related art closed glass bulb 2a contains mercury as a buffer gas, the related art mercury discharge bulb is harmful to the environment. To overcome the foregoing problem and meet the recent social demand for reduction of environmental pollutants, there has been a need to develop an arc tube containing no environmentally harmful mercury, namely a mercury-free arc tube.
Unfortunately, the foregoing related art bulb could not exclude mercury for at least the following reasons. For example, but not by way of limitation, excluding mercury from the closed glass bulb would reduce tube voltage and require an increased electrical current for maintaining the tube voltage. As a result, there would be an increased load on the electrodes, leading to a reduction in luminous efficiency. Elimination of mercury from the closed glass bulb 2a also prevents generation of light having a desired chromaticity.
To overcome at least the foregoing related art problems, applicants used a metal halide that acts as a buffer in place of mercury and realizes the same chromaticity as the foregoing related art mercury-containing arc tubes, to create a mercury-free arc tube exhibiting similar characteristics to those of the mercury-containing arc tubes, with no alterations to the shape and dimensions. This mercury-free arc tube includes a closed glass bulb filled with a primary light-emitting metal halide, together with the selected buffer metal halide and a starting rare gas. The pressure of the rare gas is about 8 to 20 atm, which is higher than in the related art mercury-containing arc tubes (3 to 6 atm). Applicants filed Japanese Patent Application No. 2001-286252, the contents of which is incorporated herein by reference.
A further modification of the foregoing mercury-free arc tube produced characteristics similar to those of related art arc tubes with no buffer metal halide sealed into the closed glass bulb. The total amount and proportion of a prescribed primary light-emitting metal halide and the pressure of the starting rare gas (about 8 to 20 atm) sealed into the closed glass bulb was maintained. Based on this modification, applicants filed Japanese patent Application No. 2002-243489 (not prior art), the contents of which is incorporated herein by reference, claiming priority to the above-noted Japanese Patent Application No. 2001-286252.
The mercury-free arc tube of JPA 2002-243489 has similar characteristics to related art mercury-containing arc tubes, and a power consumption of about 35 W, which is the same as the related art mercury-containing arc tubes.
However, users demand a reduction in the energy required to operate discharge bulbs (arc tubes). Also, the number of electric parts and accessories mounted on recent automobiles has been increasing, which has increased the total power consumption. The increased power consumption and attendant increase in harness length and weight have made it difficult to reduce vehicle fuel consumption. Although the power consumption of discharge bulbs using an arc tube as a light source (about 35 W) is lower than that of halogen lamps (about 60 W), it is still higher than most automobile electric parts and accessories. Therefore, there is a need to reduce power consumption of discharge bulbs.
To address the foregoing need to save power in a discharge bulb having the structure of JPA 2002-243489, applicants tested a reduction in electric current supplied to the arc tube from its rated value to decrease the ordinary power consumption during steady lighting from 35 W to 25 W. As a result, the tube voltage decreased from 42 V to 40 V, the tube current decreased from 0.830 A to 0.600 A, the luminous flux decreased from 3200 lm to 2000 lm, and the luminous efficiency decreased from 91 lm/W to 80 lm/W. The chromaticity also decreased.
Accordingly, applicants obtained the following conclusions with respect to applicants' related art. First, a reduction in power consumption in a steady lighting mode reduces luminous flux, which in turn reduces luminous efficiency. As a result, the brightness of the lighting area is reduced.
Second, because a slight reduction in tube voltage results in a significant reduction in tube current, the electrode temperature drops. Thus, the required re-ignition voltage increases, and causes lamp flickering.
Third, the bulb emits bluish light due to the chromaticity change from x: 0.380 and y: 0.390, to x: 0.365 and y: 0.375.
As a result, there exists a need in the related art to overcome at least the foregoing problems and disadvantages.

Mercury-free arc tube for discharge lamp unit