Vitamin and mineral absorption in warm-blooded animals is promoted by means of a class of vitamin chelates where at least one of the bonds between the metal ion and the vitamin ligand is formed between the ion and an electron rich .pi.-cloud of an aromatic ring of the water soluble vitamin. The chelate, containing a total of from one to three ligands, may contain from one up to three vitamin ligands which form a .pi.-bond with the mineral and, when present, one or two amino acid, dipeptide or tripeptide ligands. The mineral is selected from the group consisting of Fe, Cu, Zn, Mg, Mn and Ca. The water soluble vitamin ligand is preferably a residue of nicotinamide, nicotinic acid, pyridoxine, thiamine, riboflavin and folic acid. The amino acid may be any of the naturally occurring .alpha.-amino acids such as glycine. The .pi.-bond vitamin chelates are absorbed more readily from both the gastric and intestinal areas of the GI tract than vitamins or minerals administered separately or as mixtures.

The term "chelate" has often been misunderstood or applied in a general or catch-all fashion. A chelate is a definite structure resulting from precise requirement of synthesis. Proper conditions must be present for chelation to take place, including proper mole ratios of ligands to metal ions, pH and solubility of reactants. For chelation to occur, all components must be dissolved in solution and either be ionized or of appropriate electronic configuration in order for bonding to develop.
Chelation can be confirmed and differentiated from mixtures of components by infrared spectra through comparison of the stretching of bonds or shifting of absorption caused by bond formation.
As applied in the field of mineral nutrition, there are two allegedly "chelated" products which are commercially utilized. The first is referred to as a "metal proteinate." The American Association of Feed Control officials (AAFCO) has defined a "metal proteinate" as the product resulting from the chelation of a soluble salt with amino acids and/or partially hydrolyzed protein. Such products are referred to as the specific metal proteinate, i.e. copper proteinate, zinc proteinate, etc. This definition does not contain any requirements to assure that chelation is actually present. On the basis of the chemical reactant possibilities, there are some real reservations as to the probability of chelation occurring to any great degree. For example, the inclusion of partially hydrolyzed proteins as suitable ligands and the term "and/or" in reference to such ligands implies that products made solely from partially hydrolyzed protein and soluble salts would have the same biochemical and physiological properties as products made from combining amino acids and soluble metal salts. Such an assertion is chemically incorrect. Partially hydrolyzed protein ligands may have molecular weights in the range of thousands of daltons and any bonding between such ligands and a metal ion may be nothing more than a complex or some form of ionic attraction, i.e. the metal drawn in close proximity to carboxyl moiety of such a ligand.
While some products marketed as metal proteinates during the 1960's and 1970's were true chelates, this was prior to the adoption of the AAFCO definition. An analysis of products currently marketed as metal proteinates reveals that most, if not all, are mixtures of metal salts and hydrolyzed protein or complexes between metal salts and hydrolyzed protein. Most are impure products which are difficult to analyze and are not consistent in protein make-up and/or mineral content.
The second product, referred to as an "amino acid chelate", when properly formed, is a stable, product having one or more five-membered ring formed by reaction between the carboxyl oxygen, and the .alpha.-amino group of an .alpha.-amino acid with the metal ion. Such a five-membered ring is defined by the metal atom, the carboxyl oxygen, the carbonyl carbon, the .alpha.-carbon and the .alpha.-amino nitrogen and is generally represented by the following formulae. However, the actual structure will depend upon the ligand to metal mole ratio. The ligand to metal mole ratio is at least 1:1 and is preferably 2:1 but, in certain instances may be 3:1 or even 4:1. Most typically, an amino acid chelate may be represented at a ligand to metal ratio of 2:1 according to the following formula: ##STR1##
In the above formula, when R is H, the amino acid is glycine which is the simplest of the .alpha.-amino acids. However, R could be representative of any other the other twenty or so naturally occurring amino acids derived from proteins. These all have the same configuration for the positioning of the carboxyl oxygen and the .alpha.-amino nitrogen. In other words, the chelate ring is defined by the same atoms in each instance. The American Association of Feed Control Officials (AAFCO) have also issued a definition for an amino acid chelate. It is officially defined as the product resulting from the reaction of a metal ion from a soluble metal salt with amino acids with a mole ratio of one mole of metal to one to three (preferably two) moles of amino acids to form coordinate covalent bonds. The average weight of the hydrolyzed amino acids must be approximately 150 and the resulting molecular weight of the chelate must not exceed 800. The products are identified by the specific metal forming the chelate, i.e. iron amino acid chelate, copper amino acid chelate, etc.
The reason a metal atom can accept bonds over and above the oxidation state of the metal is due to the nature of chelation. In Formula I it is noted that one bond is formed from the carboxyl oxygen. The other bond is formed by the .alpha.-amino nitrogen which contributes both of the electrons used in the bonding. These electrons fill available spaces in the d-orbitals. This type of bond is known as a dative bond or a coordinate covalent bond and is common in chelation. Thus, a metal ion with a normal valency of +2 can be bonded by four bonds when fully chelated. When chelated in the manner described the divalent metal ion is completely satisfied by the bonding electrons and the charge on the metal atom (as well as on the overall molecule) is zero. This neutrality contributes to the bioavailability of metal amino acid chelates.
Amino acid chelates can also be formed using peptide ligands instead of single amino acids. These will usually be in the form of dipeptides or tripeptides because larger ligands would have a molecular weight which would be too great for direct assimilation of the chelate formed. Generally, peptide ligands will be derived by the hydrolysis of protein. However, peptides prepared by conventional synthetic techniques or genetic engineering can also be used. When a ligand is a di- or tripeptide a radical of the formula [C(O)CHRNH].sub.e H will replace one of the hydrogens attached to the nitrogen atom in Formula I. R, as defined in Formula I, can be H, or the residue of any other naturally occurring amino acid and e can be an integer of 1 or 2. When e is 1 the ligand will be a dipeptide and when e is 2 the ligand will be a tripeptide.
The structure, chemistry and bioavailability of amino acid chelates is well documented in the literature, e.g. Ashmead et al-. , Chelated Mineral Nutrition, (1982), Chas. C. Thomas Publishers, Springfield, Ill.; Ashmead et al., Intestinal Absorption of Metal Ions, (1985), Chas. C. Thomas Publishers, Springfield, Ill.; Ashmead et al., Foliar Feeding of Plants with Amino Acid Chelates, (1986), Noyes Publications, Park Ridge, N.J. as well as in U.S. Pat. Nos. 4,020,158; 4,167,564; 4,216,143; 4,216,144; 4,599,152; 4,774,089; 4,830,716; 4,863,898 and others. Flavored effervescent mixtures of vitamins and amino acid chelates for administration to humans in the form of a beverage are disclosed in U.S. Pat. No. 4,725,427.
One advantage of amino acid chelates in the field of mineral nutrition is attributed to the fact that these chelates are readily absorbed in the gut and mucosal cells by means of active transport as though they were amino acids. In other words, the minerals are absorbed along with the amino acids as a single unit utilizing the amino acids as carrier molecules. Since this method of absorption does not involve the absorption sites for free metal ions, the problems of competition of ions for active sites and suppression of one nutritive mineral element by another are avoided.
The importance of vitamins and minerals in proper nutrition has long been recognized. However, it is generally thought that the absorption of vitamins and minerals is independent of each other. Even when marketing vitamin and mineral combinations, such as taught in U.S. Pat. No. 4,725,427, the vitamin and mineral ingredients are admixed and coadministered as separate entities.
There has been some discussion of some interaction between nicotinic acid, amino acids and chromium and niacinamide and cobalt in conjunction with certain amino acids and/or small peptides as they relate to components forming the glucose tolerance factor (GTF). Mertz et al., "Present Knowledge of the Role of Chromium", Federation Proc., 23(11) pp. 2275-2280 (1974) reported that, in efforts to purify the GTF, there was detected chromium, nicotinic acid, glycine, glutamic acid and cysteine. A possible structure for a dinicotinato-amino acid Cr-complex was proposed consisting of approximately 2 moles each of nicotinic acid and glycine and one mole of cysteine per chromium atom. It was readily acknowledged that the exact structure was not known. Toepfer et al., "Preparation of Chromium-Containing Material of Glucose Tolerance Factor Activity from Brewer's Yeast Extracts and by Synthesis", J. Agric. Food Chem., 25(1) pp. 162-166 (1977) report the synthesis of a chromium complex containing two moles nicotinic acid, 2 moles glycine, 1 mole glutamic acid and 1 mole of cysteine per chromium atom. Further reported is the formation of complexes of chromium with nicotinic acid alone in a presumably dinicotinato, tetaaquo configuration. This complex was stated to be unstable and rapidly lost biological activity. The formation of other complexes of chromium and nicotinic acid with other amino acids was alluded to but not specifically demonstrated. While Toepfer et al. reported GTF type biological activity it was stressed that the structure of the complexes formed was only speculative. Silio, "Process for Obtaining a New Glucose Tolerance Factor", U.S. Pat. No. 4,242,257 (1980) suggests the formation of a complex between cobalt and nicotinamide which is then reacted with the tripeptide, glutathione, to form a product having GTF activity. No structure is proposed and the reaction must be carried out stepwise with the complex between the chromium salt and nicotinamide first being formed, acidified and then reacted with glutathione.
An excellent summary of the state of the art relative to the structure and synthesis of complexes exhibiting GTF activity is found in Jensen, Synthetic GTF Chromium Material and Process Therefor, U.S. Pat. No. 4,923,855 (1990). Jensen lists several proposed structures including chromium and nicotinic acid showing dative or coordinate covalent bonding between the nitrogen atom of the pyridine ring and also involving the carboxyl oxygen of the --COO.sup.- of the nicotinic acid. Jensen quite clearly states that the structure formed from the reaction of nicotinic acid and chromium is not known with any degree of certainty. A proposed reaction sequence is given on col . 5 and a trinicotinate structure is proposed at the top of col. 6. However, it is stated at lines 25-38 of col. 6 that it is likely that the reaction illustrated does not go to completion. It is speculated that some dinicotinate and perhaps even some mononicotinate or even pentanicotinate may be formed.
Weismann, "Chelating Drugs and Zinc", Dan. Med. Bul., 33 208-211 (1986) states that, in nature, there are various vitamin-metal complexes formed such as Zn-thiamine, Zn-pyridoxamine and Zn-biotin. Several "drugs" are also mentioned and structures are proposed for Zn-drug complexes, none of which involve vitamins. However, each structure proposed shows the conventionally described chelate bond, i.e. between the zinc ion and an amine or OH group. No .pi.-cloud or resonance bonding is taught or even suggested.
While the above mentioned complexes and chelates are of interest both from the standpoint of their biological activity and structure, they are limited in scope to certain types of activity and, for the most part, involve only the metal ions Co and Cr which are present in only very minute amounts in complexes exhibiting GTF type activity or in alleged naturally occurring Zn vitamin complexes. It would be desirous to formulate a class of chelates which would simultaneously provide the benefits of vitamins and a broad class of the minerals most commonly required in biosystems, e.g. Fe, Cu, Mn, Zn, Ca and Mg, combined in a single molecule having superior bioavailability for both mineral and vitamin.


A semiconductor device includes an interlayer insulating layer disposed over a semiconductor substrate, and including a plurality of wiring layers; a seal ring disposed in the interlayer insulating layer, and surrounding a circuit region of the semiconductor substrate; a crack lead ring disposed in the interlayer insulating layer, and surrounding the seal ring; and a protective film disposed over the interlayer insulating layer, and covering the crack lead ring and the seal ring. The crack lead ring includes an uppermost wiring layer in an uppermost layer of a plurality of wiring layers. When the crack lead ring has a wiring in an underlayer below the uppermost layer, the uppermost layer wiring extends towards the outside of the device, relative to the wiring in the underlayer. The protective film has an end overlapped with an end of the uppermost layer wiring to form a step over the interlayer insulating layer.

The present invention relates to a semiconductor device, and more particularly to a technique suitable for use in a semiconductor device into which, for example, a semiconductor wafer is diced.
In a manufacturing process of the semiconductor device, a plurality of semiconductor devices are formed over the semiconductor wafer. Thereafter, the semiconductor wafer is diced to separate the individual semiconductor devices as semiconductor chips. In this situation, a crack may be generated in an end (scribe line region) of each semiconductor chip by dicing, and spread into a circuit region within the semiconductor chip. As a technique for preventing the spread of the crack, a seal ring (or a guard ring) is known in the prior art. The seal ring is formed of a metal member stacked to penetrate through a plurality of inter-layer insulating films disposed over a semiconductor substrate. The seal ring is annularly disposed to surround the circuit region.
For example, Japanese Unexamined Patent Application Publication No. 2004-304124 (US2004/0195582(A1)) discloses a semiconductor device. The semiconductor device has a circuit formation region which is a region of a circuit formed over the semiconductor substrate. The semiconductor device includes a first guard ring, a second guard ring, and a first connection portion. In order to prevent moisture from entering the circuit formation region from a periphery thereof, the first guard ring surrounds the periphery of the circuit formation region. The second guard ring is disposed between the circuit formation region and the first guard ring, and surrounds the periphery of the circuit formation region. The first connection portion connects the first guard ring and the second guard ring, and divides a region between the first guard ring and the second guard ring into a plurality of sections. In this technique, in order to prevent the entry of moisture, the seal ring that surrounds the circuit formation region is as least doubled, and the respective seal rings are connected to each other. With this configuration, moisture is prevented from entering the circuit formation region, and a crack generated at the time of dicing is prevented from spreading into the circuit formation region.
Also, Japanese Unexamined Patent Application Publication No. 2004-153015 (US2004/0084777(A1)) discloses a semiconductor device and a manufacturing method thereof. The semiconductor device includes a first insulating film, a second insulating film, a wiring structure, a first dummy pattern, and a second dummy pattern. The first insulating film is formed over the semiconductor substrate. The second insulating film is formed over the first insulating film. The wiring structure is embedded in the first insulating film and the second insulating film. The first dummy pattern is formed of a first conductive layer embedded in at least a surface side of the first insulating film in the vicinity of the wiring structure. The second dummy pattern is formed of a second conductive layer embedded in the second insulating film in the vicinity of the wiring structure, and connected to the first dummy pattern through a via hole portion. In this technique, an interlayer insulating film disposed in the vicinity of the wiring structure (guard ring) is reinforced by the dummy patterns to prevent a crack or separation from being generated on an interface or in an interior of the interlayer insulating film.

Semiconductor device having crack-resisting ring structure and manufacturing method thereof


Displacements of output portions 35, 36 of a pair of piezoelectric actuators 25, 26 arranged spanwise in a flap drive apparatus are magnified by a displacement magnification mechanism 27 so that a swing arm 28 is driven in swinging fashion with large amplitude. A flap 22 attached to the trailing edge of a blade 21 by way of a connecting rod 30 connected to a tip of the swing arm 28 is driven in vertical angular displacement fashion. The displacement magnification mechanism 27 possesses an eccentric shaft 40 has a first shaft 41 and second shaft 42 with offset axes. An output portion 35 is coupled to the first shaft 41, and an output portion 36 is coupled to the second shaft 42. The swing arm 28 is fixed to the eccentric shaft 40. Displacement of the output portions 35, 36 of the actuators 25, 26 in opposite phase results in a stable swing of the swing arm 28.

1. Technical Field
The present invention relates to a rotor blade flap drive apparatus that drives a flap provided at a trailing edge of each rotor blade in a helicopter or the like.
2. Background Art
In recent years, demand has increased for commuter helicopters that take off and land at urban heliports. To realize this operation, noise reduction of helicopters is strongly required. As one effective means for accomplishing such a noise reduction strategy, a technique is contemplated wherein a flap is attached to a helicopter rotor blade and drives those flap at a high speed of approximately 30 Hz to 50 Hz in order to improve aerodynamic characteristics of the rotor blade.
As an apparatus for realizing high-speed driving of a flap in this manner, the present applicant has proposed the rotor blade flap drive apparatus of Japanese Patent Application No. 10-076246 (1998). In order to be housed within the blade, an actuator employed by the flap drive apparatus should be small and lightweight, and in the aforementioned rotor blade flap drive apparatus a piezoelectric actuator is used as the actuator therein. Because piezoelectric actuator displacement is very small, in driving the flap, actuator displacement is magnified by means of a displacement magnification mechanism.
FIG. 16 is a plan view showing one example of such a conventional rotor blade flap drive apparatus 1, and FIG. 17 is a side view thereof. In the rotor blade flap drive apparatus 1, an eccentric shaft 3 is employed as a displacement magnification mechanism 2. Eccentric shaft 3 possesses a first shaft 12 and a second shaft 13 having mutually eccentric axes 10, 1, and a bearing 4 which supports the first shaft 12 is fixed relative to the blade. Output portions 6a, 7a of two actuators 6, 7 are coupled by way of a coupling member 14 to a bearing 5 which supports the second shaft 13. Fixed to this eccentric shaft 3 is a swing arm 8, and a connecting rod 9, which is, coupled to the tip of this swing arm 8, is connected to-the flap.
Simultaneous extension/contraction of the two actuators 6, 7 causes reciprocating angular displacement of the eccentric shaft 3 about the axis 10 of the first shaft 12, which is supported fixedly relative to the blade, resulting in large lead-lag swing of the swing arm 8 which is fixed to this eccentric shaft 3. Swing of the swing arm 8, which is thus made to swing-in a lead and lag direction with large amplitude, is transmitted by way of the connecting rod 9 to the flap, resulting in the flap motion in vertical reciprocating angular displacement fashion.
In order to obtain a large driving force with such a flap drive apparatus 1, the two actuators 6, 7 are employed, as has been described above, and the respective actuators 6, 7 are driven in synchronous fashion. The output portions 6a, 7a of the two actuators 6, 7 are fixed together in an integral fashion by the coupling member 14, and are coupled to the bearing 4 for the second shaft 13 of the eccentric shaft 3. Accordingly, while there is no Ads problem when the two actuators 6, 7 are displaced in proper synchronous fashion, even a slight disagreement in synchronization will result in slight distortion at the periphery of the eccentric shaft 3, causing a large reduction in the displacement magnification factor and resulting in swing instability. Furthermore, it is extremely difficult to control the actuators 6, 7, which are displaced at high speed, such that they are synchronized with high precision.
The object of the present invention is to provide a rotor blade flap drive apparatus having a simple construction and being capable of causing stable swing of a swing arm in a displacement magnification mechanism.
The invention provides a rotor blade flap drive apparatus comprising: a flap attached to a trailing edge of a blade so as to permit vertical angular displacement, and a pair of actuators housed within the blade and having output portions which are displaced in mutually reverse phases. A swing arm has a base portion which forms a side end of the actuator and is coupled to the respective output portions of the pair of actuators so as to be angularly disposed, and has a tip that swings in a lead and lag direction, and which is at a side opposite to the base portion. A connecting rod connects the tip of the swing arm and the flap.
In accordance with the present invention, the two actuators have output portions that are displaced in mutually reverse phase. That is, when one of the actuators is extended the other actuator contracts, and conversely, when one of the actuators contracts the other actuator is extended.
Accordingly, the tip of the swing arm, the base portion of which is coupled to the output portions of two such actuators, will as a result hereof swing in a lead and lag. direction with large amplitude, and the swing of the swing arm will, by way of the connecting rod, cause vertical reciprocating angular displacement of the flap.
With the above-described conventional flap drive apparatus, the two actuators are extended/contracted simultaneously in synchronous fashion and the output portions are fixedly coupled. Therefore, even a slight disagreement in synchronization causes the swing arm to no longer swing smoothly but rather to become unstable. In contrast, in the present invention swing is made to occur such that the output portions of the two actuators are displaced so as to be mutually reverse in phase. Therefore, the swing arm swings about an imaginary central swing axis located centrally between respective output portions. Accordingly, even when the phases of the two actuators are not exactly reverse but are in slight disagreement, the location of the imaginary central axis of swing of the swing arm will simply be displaced slightly and there will be no reduction in displacement magnification factor, permitting automatic adjustment of swing. The swing arm can thus be made to swing stably through employment of a simple structure.
Furthermore, in the conventional method, the angle of the swing arm would be changed in the event that a large centrifugal force caused application of a compressive force on the actuator and slight contraction of the actuator. However, the present invention has the advantage that because the angle of the swing arm will remain unchanged, there is no need to take into account the effect of the magnitude of the centrifugal force on the angle of the swing arm.
Moreover, because in the invention the swing arm is made to swing through use of the difference in phase between the output portions of two actuators (as compared with the conventional structure wherein actuators are simultaneously extended/contracted in synchronous fashion), it is possible to achieve output displacement magnification relative to actuator displacement that are approximately two times those of flap drive apparatuses having conventional structures.
In the invention it is preferable that the apparatus comprises an eccentric shaft in which a first shaft and a second shaft have axes that are mutually parallel and are mutually eccentric in a direction perpendicular to the axial direction, and the shafts are connected end-to-end in the axial direction to form an integral structure. A first support supports the first shaft so as to permit angular displacement, and the first support is coupled to the output portion of a first one of the actuators. A second support supports the second shaft so as to permit angular displacement, and the second support is coupled to the output portion of the second one of the actuators. The swing arm is fixed to a periphery of the eccentric shaft perpendicularly with respect to the eccentric shaft.
In accordance with the present invention, actuator displacement is magnified by the eccentric shaft and the swing arm which is fixed to the eccentric shaft. Because the magnification factor is determined by the ratio between the amount of eccentricity and the length of the swing arm, the amount of eccentricity must be made small in order to reduce the size of construction and increase the size of the magnification factor. Furthermore, the first shaft and the second shaft, as well as the first bearing and the second bearing which support these, must inevitably be made large for stable driving of the swing arm. Arranging the first and second shafts in parallel would also make it unavoidable for the amount of eccentricity to be made large. However, the invention permits the amount of eccentricity to be made as small as possible and the magnification factor to be made as large as possible as a result of the fact that the first shaft and the second shaft are connected end-to-end in the axial direction to form an integral structure. Furthermore, this also makes it possible for the first bearing and the second bearing, which support the respective shafts, to be arranged such that they are offset in the axial direction, permitting stable support.
Furthermore, in the invention it is preferable that the swing arm comprises a tip that swings in a lead and lag direction, and a base portion having two axes extending vertically and arranged such that they are spaced apart in the lead-lag direction. The output portion of a first one of the actuators is coupled to one of the lead-wise and lag-wise base portion axes so as to permit angular displacement, and the output portion of the second one of the actuators is coupled to the other of the lead-wise and lag-wise base portion axes so as to permit angular displacement.
In accordance with the invention, respective output shafts of the two actuators arranged in the lead and lag direction are coupled to the base portion of the swing arm so as to permit angular displacement. Accordingly, displacing the respective output shafts in opposite directions such that they are reverse in phase causes the tip of the swing arm to swing in a lead and lag direction with a large amplitude, and causes the flap to be driven vertically in a reciprocating angular displacement fashion by way of the connecting rod which is connected to the tip. The swing arm can thus be driven stably through employment of such a simple construction.
In the invention, it is further preferable that the swing arm comprises a pair of links, with a base portion of a first one of the links being coupled to the output portion of a first one of the actuators so as to permit angular displacement, and a base portion of the second one of the links being coupled to the output portion of the second one of the actuators so as to permit angular displacement. A tip of the first one of the links and a tip of the second one of the links are coupled so as to permit angular displacement, and the connecting rod is connected to these tips.
In accordance with the present invention, the swing arm is constructed in a so-called toggle-link fashion, which is to say that base portions of respective links are coupled to the output portions of the respective actuators so as to permit angular displacement, and-the tips are coupled to each other. With such a toggle-link-type swing arm as well, displacing respective actuator output portions in reverse phase causes the tip to swing in a lead and lag direction with a large amplitude, and causes the flap to be driven vertically in a reciprocating angular displacement fashion by way of the connecting rod which is connected to the tip. In this way, the output portions displaced in reverse phase and the toggle-link-type swing arm permits stable swinging drive of a swing arm.
Moreover, in the invention it is preferable that the apparatus comprises linear guide means mounted within the blade so as to allow the output portion of one of the actuators to undergo displacement only along a-displacement direction of the actuator thereof but preventing the output portion from undergoing displacement in a direction perpendicular to the displacement direction of the actuator.
In accordance with the present invention, because the output portion of one of the actuators undergoes displacement properly in a linear direction through the use of a linear guide means, the reactive force of the flap which acts by way of the connecting rod is generated by the linear guide means, permitting the swing arm to be driven stably and properly. Because the construction is such that the swing arm is made to swing as a result of causing the respective output portions which are coupled to the base portions of the swing arm to provide linear displacement so as to be more or less mutually parallel and reverse in phase, the paths of motion of the respective output portions are not perfectly parallel lines but paths of motion that bulge slightly in the central region in the displacement direction. Accordingly, by providing linear guide means at the output portion of only one of the actuators and not at the other, a slight difference in path of motion is allowed, permitting the swing arm to be driven stably and properly.
Furthermore, in the invention it is preferable that the apparatus comprises a spring member intervening between the swing arm and the blade. This causes action, when the swing arm is angularly displaced to either side of a neutral position thereof, of a spring force in such a direction to encourage such angular displacement.
In accordance with the invention, when the swing arm is angularly displaced to either side past its neutral position, a spring force from the spring member causes encouragement of that angular displacement, and rapid angular displacement to the full-stroke position on that side is obtained. Conversely, when the swing arm is angularly displaced from this side to the other side, past the neutral position, angular displacement to the other side is encouraged. Accordingly, by causing a lead-lag swing of the swing arm centered on its neutral position through the use of the actuators, it is possible to enable the swing arm to undergo reliable, rapid reciprocating angular displacement through its full stroke. It is thus possible to improve response through employment of such a simple construction.
Furthermore, this spring force acts so as to cancel the hinge moment acting on the flap and so as to assist driving of the flap by the actuators.
Moreover, in the invention it is preferable that the apparatus comprises a spring member intervening between the flap and the blade, for causing action, when the flap is angularly displaced to either side of a neutral position thereof, of a spring force in such a direction to encourage such angular displacement.
In accordance with the invention, the flap is equipped with a spring member in the same manner as the foregoing, and this spring member is arranged such that when the flap is angularly displaced upwardly past its neutral position, the spring member encourages the angular displacement and causes angular displacement to the upward limiting position. Conversely, when the flap is angularly displaced downwardly past its neutral position, the spring member causes driving of the angular displacement to the downward limiting position. Response can thus be improved through employment of a simple construction.
Furthermore, like the above-described spring provided at the swing arm, this spring is also such that the spring force therefrom causes cancellation of the hinge moment acting on the flap and acts so as to assist the actuators.
Furthermore, in the invention it is preferable that the apparatus comprises a spring actuator intervening between the spring member and the blade, for applying variation of the spring force from the spring member.
The hinge moment acting on the flap varies cyclically with blade rotation and so forth. A spring actuator is provided at the spring member attached to the swing arm or the flap, permitting spring force to be varied by means of this actuator. Accordingly, by using the spring actuator to vary spring force corresponding to the hinge moment acting on the flap, it is possible to assist actuator movement with optimum force.
Furthermore, in the invention it is preferable that the apparatus comprises an input shaft parallel to the axis of the flap angular displacement shaft and fixed to the flap angular displacement shaft eccentrically in a vertical direction. A rod end supports the input shaft so as to permit angular displacement, and connects the connecting rod thereto perpendicularly with respect to the axis of the input shaft.
In accordance with the present invention, input of a displacement from the connecting rod, which undergoes displacement lead and lag direction, to the input shaft, which is fixed eccentrically to the flap angular displacement shaft, causes the displacement of the connecting rod to be magnified, the input arm length being the amount of eccentricity, and causes the flap to undergo angular displacement with a large amplitude. The flap can thus be made to stably undergo magnified displacement through employment of the eccentric input shaft and the rod end which supports the input shaft.
Moreover, in the invention it is preferable that the actuators comprise stack-type piezoelectric actuators in which a plurality of piezoelectric element sheets that undergo displacement in correspondence to a voltage applied thereto are laminated. The sheets are arranged such that a displacement direction thereof is in a blade spanwise direction, and the ends of the actuators at the blade tip side are fixed to the blade.
It is necessary to apply a preload to a stack-type piezoelectric actuator such that it is compressed in the displacement direction during operation. In the invention, however, the actuators are arranged so as to lie along the blade spanwise direction, and the ends of the actuators at the blade tip side are furthermore fixed to the blade. Therefore, the centrifugal force produced during rotation of the rotor blade causes application of a preload on the actuators. As a result, the need to use a spring or the like to apply a preload is eliminated, permitting reduction in the number of components and simplification of the construction.
Furthermore, in the invention it is preferable that the actuators comprise giant magnetostrictive actuators that are displaced as a result of a change in a magnetic field produced by an electric current through an electromagnetic coil. The actuators are arranged such that the displacement direction is in a blade spanwise direction, and one end of each of the actuators at the blade tip side is fixed to the blade.
While it is also necessary to apply a preload to a giant magnetostrictive actuator in the displacement direction, because the actuators are arranged so as to lie along the spanwise direction and because the ends of the actuators at the blade tip side are fixed to the blade, the centrifugal force produced during rotation of the rotor blade causes application of a preload on the actuators. As a result, the need to use a spring or the like to apply a preload is eliminated, permitting reduction in the number of components and simplification of the construction.

Advanced Technology Institute of Commuter-Helicopter, Ltd.


A method is disclosed for testing a high speed microcontroller fabricated on a semiconductor chip, and for testing relatively low speed functions of a liquid crystal display (LCD) module on the chip that drives an off-chip LCD for an external system to be controlled by the microcontroller with a plurality of discrete analog voltage levels for performing the LCD functions. Digital values are multiplexed in time slots of a test waveform to simulate in high speed digital format of a test mode the low speed timing, relative magnitude and functionality of analog voltage levels used to drive the LCD; A high speed driver is selectively coupled to a pin of the chip, to which the discrete analog voltage levels are normally applied at low speed to drive the LCD, and the test waveform is applied to the high speed driver. The digital values and timing that appear on the pin are then monitored as an indication of proper functionality of the LCD module. The high speed driver is switched out and the normal low speed LCD driver is switched back for return to an LCD user mode when the test mode is completed. Monitoring the pin with a digital tester allows verification that pin pulses in predetermined time slots indicate the corresponding analog voltage level is being applied at the proper time during normal operation of the LCD module, and digitally testing of continuity in an analog channel. A transistor normally employed on the chip for electrostatic discharge protection is activated to selectively couple the high speed driver to the pin for the high speed testing mode.

The present invention relates generally to microprocessors especially adapted to provide control functions for external systems or subsystems, and thus generally referred to as microcontrollers, and more particularly to microcontrollers which are capable of providing liquid crystal display (LCD) driver functions without need for peripheral elements other than the display itself.
An LCD generally comprises a pair of glass plates between which a liquid crystal material is sandwiched, the liquid crystal having the property of undergoing orientation of its crystal-like structure according to an electric field placed between transparent electrically conductive material on the plates, and thereby causing a selective darkening of the respective pixels with the passage of light through the liquid crystal to render the darkened pixels visible to the eye. The typical LCD, such as that shown in FIG. 1, which illustrates a panel 10 of the prior art, employs a plurality of commonly formed, potential alphanumeric characters 12. Each of the characters is in the form of a block figure "8" shape composed of a plurality of individual lineal pixels 15--typically seven as shown in the Figure, although more may be used where greater curvature or detail of reproduction of the particular alphanumeric character to be displayed is desired. In the seven pixel character, three horizontal pixels such as 17, 18, and 19 are vertically aligned and equally spaced apart, and two vertical aligned pixels 21, 22 (and 23, 24) are positioned at each end of the array of horizontal pixels bounding the respective spaces between the latter.
The pixels are conventionally driven by waveforms applied to a digitally encoded array of electrical conductors of printed circuit form (not shown in FIG. 1), each of the conductors on the top side of the LCD being connected to "segments", while the conductors on the bottom are connected to "commons". Hence, when a particular digital code (e.g., binary-based) is applied in the form of an electrical energization of the various conductors, a particular alphanumeric character is displayed on the LCD--assuming, of course, the presence of a source of light emanating through the plates. The "segments" are electrically energized by drivers which are supplied as part of a peripheral device, typically on a semiconductor circuit chip (not shown in FIG. 1). The "commons" are also driven by the semiconductor circuit chip in such a way that the RMS voltage across each of the pixels will be either above a threshold value (pixel dark) or below that threshold value (pixel clear). For any given LCD, the product of the number of "commons" multiplied by the number of "segments" is equal to the number of pixels in the display.
LCDs are used in a wide variety of applications including home security systems, industrial control thermostats, home thermostats, blood pressure meters, blood glucose meters, AC power meters, toys, voice recorders, microwave ovens, and carbon monoxide detectors, to name but a few. The use of LCDs in such applications, and in which one or more microcontrollers is used to control the system constituting the application in which the LCD is used, is, in and of itself, quite conventional. Heretofore, however, the display (which may include a large number of pixels) has been operated and controlled by its own power source and control devices, while the system in which or with which the display is used is separately controlled by the microcontroller. The requirement of separate control devices has adversely affected the cost, complexity, and size of the overall control portion of the system.
The nature of the problem may be better understood by reference to a relatively simple example of a thermostat which is used to control the temperature of the air in an enclosure by means of control exercised on a heating, ventilating, and air conditioning (HVAC) system for the enclosure. A thermistor provides an analog input indicative of the temperature of the air in the enclosure. An LCD display provides a visual indication of that temperature, and also displays a set point or set temperature which is designated by the user by appropriate selection using a keypad. An interrupt is provided by a keypad interface that allows the user to punch in certain keypad information as references which are used by the microcontroller to change the display, such as to write another output into memory--a select voltage for the thermostat output at which the microcontroller will turn on a heat pump in the system.
It would be desirable to consolidate everything, or at least a substantial part of the control functions, within a single product--namely, the microcontroller chip itself. Such a goal, however, is by no means a simple task. An LCD display operates at a considerably slower speed than a microcontroller. Also, the timing of the microcontroller control functions is different from the timing of the LCD control functions. Another issue arises in connection with the capability of a microcontroller to be placed in a "sleep" mode or sleep state to conserve power, whereas the LCD display must continue to function.
Present-day systems that control an LCD display which itself is used in conjunction with a system to be controlled by a microcontroller require a source of clock pulses to control the timing and updating of the display, among other things, when not supplied by the microcontroller itself, as when the latter is in its sleep mode. Although the microcontroller device package typically has a pin available for an external input, the device user may not wish to use that capability, preferring to reserve it for other essential purposes. For the LCD to remain operational, the timing module must supply clock signals to the logic section which drives the LCD display. In a typical present-day application, currently available microcontrollers are incapable of providing any clock function when in the sleep state.
If the device user's application requires that the LCD display must or should remain operational, it becomes necessary for the user to employ a separate device that will make external clock signals available for LCD control, by applying the external clock to an external pin of the microcontroller. This means that the selected pin (only a finite number of which are available--in a typical device, only one, or perhaps two) will be unusable for another purpose. And the other purpose may be much more essential in an emergency situation.
Two types of waveforms are variously used to drive an LCD display, as will be described in greater detail below. A type A waveform generates "common" and "segment" waveforms, with all data contained in a single frame and assembled in complementary fashion, such as high voltage and low voltage, to produce a DC value of zero for that frame. It is essential that the voltage waveform across the glass plates of the display be maintained at an average DC value of zero because the glass is likely to suffer a breakdown if a non-zero DC voltage is applied for any sustained period of time. A type B waveform generates "common" and "segment" waveforms with ,all of the data in two frames, the actual data being assembled in a first frame and that same data being assembled in inverse form in a second frame, such that an average DC value of zero is maintained for the type B waveform over a full two frames of data.
Generally, the type A waveform is employed for simple LCD displays, and the type B waveform is utilized for more complex LCD and higher MUX rate displays, the latter because of a better discrimination ratio for the type B which produces an enhanced viewing angle. To turn an LCD pixel on, the RMS voltage of either waveform must exceed the threshold voltage of the glass (or, more accurately, of the capacitive element constituting the electrically conductive confronting pixels), and to turn the pixel off, the RMS voltage value must be below that threshold voltage. The contrast in the display increases to a limited extent with increases in RMS voltage above the threshold voltage of the glass. A significant problem arises in the manner in which the waveform voltages are developed to drive the LCD efficiently from the microcontroller.
Because the type A waveform supplies data read from a random access memory (RAM) in a single frame of zero DC value, the RAM can be read or written to at any time. In contrast, with the type B waveform, since two frames are required over which to achieve the zero DC value it is necessary to retain the data in the RAM for that entire period, i.e., two frames or cycles of the waveform. A change of data in the RAM before the second frame is completed, for example, could result in the second frame not containing the inverse of the data in the first frame, and a resultant non-zero DC value.
The frame rates for LCD control are very slow, relatively, residing in the 60 to 100 hertz (Hz) range, whereas the microcontroller typically operates at rates of one megahertz (MHZ) or higher. With the fast-running microcontroller, it becomes difficult to maintain a DC value of zero in the type B waveform simply because data may be changing so rapidly. So the reliability and physical instability of the LCD glass itself presents a problem in operating an LCD display from a control function consolidated with the microcontroller.
Yet another substantial problem resides in the manner in which a consolidated LCD-functional microcontroller may be tested. The very slow speed LCD display poses serious problems in devising test methodology that will allow the microcontroller to be tested in a manner suited to its operating speed and which is not wasteful of test time or test cost. Moreover, the analog voltages and functions to be accommodated for the LCD conflict with a desire to conduct testing of the microcontroller on a digital tester or using digital simulations.
Another series of problems is encountered when the semiconductor substrate in which the microcontroller is fabricated is P-type rather than N-type. The conductivity of the P-type substrate makes it necessary to operate with positive voltages, including the development of positive voltages to operate and enable the various functions of the LCD display and its control.
A principal aim of the present invention is to provide a microcontroller device which efficiently and economically consolidates LCD control functions with system control functions of the microcontroller. More particularly, it is an object of the invention to consolidate into one part--one product--an analog interface for receiving and transmitting analog voltage (or other waveform) inputs and outputs, an LCD interface for updating the LCD display, and the microcontroller instructions and sequencer for performing control operations.
A related object is to incorporate at least a portion of the capability to control an LCD of a microcontroller-controlled system within the microcontroller chip itself.
Another principal aim of the present invention is to provide a test methodology for testing the microcontroller in a manner suited to its operating speed, with conservation of test time and cost, despite the slow operating speed of the on-chip control module for the LCD.

Method and apparatus for testing a relatively slow speed component of an intergrated circuit having mixed slow speed and high speed components


A system for presenting telecommunication services to potential customers can include a distributed, platform independent registry disposed within a publicly accessible network. The registry can include a plurality of entries, each entry specifying at least one telecommunication service, wherein selective ones of the telecommunication services can be provided by two or more providers. Each entry can further contain connectivity information for contacting an associated one of the providers across a publicly accessible network in order to obtain the telecom service from the provider. Each of the telecommunication services can be configured to function within multiple switch environments.

1. Technical Field
The present invention relates to the field of telecommunications and, more particularly, to a publicly accessible registry listing telecommunication services.
2. Description of the Related Art
Telecommunication (telecom) companies offer customers numerous telecom services, such as caller ID, voice mail, and three way calling, either singularly or as part of a telecom package. As sales and usage of personal telecom devices, such as cellular telephones and personal data assistants (PDAs), have increased, the demand for telecom services has escalated. Unfortunately, the marketplace for telecom services has not kept pace with increasing consumer demands.
One reason the supply for telecom services has failed to fulfill the demand can originate from the manner in which telecom services are implemented. Generally, telecom services are developed specifically for a particular telecom switch. Development of new services typically requires specialized personnel having a significant amount of experience in programming a particular telecom switch upon which a telecom service is to be implemented. Further adding to the cost of telecom service development, is the fact that telecom services are not easily ported from one type of telecom switch to another. Consequently, similar and like features must be redesigned for each switch.
Moreover, a confused marketplace exists for telecommunication services. First, no agreed upon standardized set of terms or phrases describing telecom services exists through which meaningful comparisons among services can be made. Additionally, an existing customer base has been trained to select packages of telecom services instead of choosing among individual telecom services capable of suiting individual requirements. In consequence, consumers do not request individual telecom services in a competitive fashion.
Telecom carriers also lack the ability to exchange and transfer individual services among themselves responsive to consumer demand. For example, suppose a first telecom service provider supplied a three way calling service desirable to a selected business, but that business needed caller ID features which are not available through the first telecom provider. Absent some third party bundling of a caller ID feature to be included with the first provider's telecom service, the business would not be able to utilize the desirable three way calling service. Similarly, customers transferring from one telecom carrier to another are typically forced to discontinue telecom services proven satisfactory, merely because such services are not supported by the new telecom carrier.
Many industry leaders have directed efforts that focus upon expanding the portability of telecom services and increasing the pool of available developers. For example, such standardization efforts as Intelligent Networks (IN), Advanced Intelligent Networks (AIN) and Java Advanced Intelligent Network (JAIN®) focus upon providing a telecom architecture that separates service logic from switching equipment. While these efforts enhance telecom services portability, the efforts do little to create a marketplace wherein suppliers of telecom services can present telecom products to customers.

International Business Machines Corporation


A flotation device includes an elongated and flexible member with a channel extending between longitudinal ends of the flexible member. The flexible member is configured to support an individual within water during a recreational activity. A cap is secured to the flexible member having a shaft suitably dimensioned to fit within the channel of the flexible member to secure the cap to the flexible member. A sleeve having a body member is dimensioned to fit over the flexible member and act as the flexible member's skin. The sleeve can also be dimensioned to fit over the flexible member and the cap for acting as the flexible member's and the cap's skin. The flexible member has at least one cut-out which corresponds to or is aligned with at least one cut-out of the sleeve.

1. Technical Field
The present disclosure relates to an elongated, recreational flotation device for use in pools and other bodies of water.
2. Description of the Related Art
Flotation devices, such as inflatable or floating rafts, are well known for use in recreational water activities. One particular device that has recently become popular for use in pools and at beaches is an elongated flotation device that is shaped in the form of a noodle and is made of a flexible material (e.g., foam) that has a sufficient buoyancy to support a user at the water surface during use.
It is desirable to provide floatation devices that have simple designs and provide additional recreational and aesthetic features.


A liquid crystal display having an improved display characteristic and having a ring-structured storage capacitor of an independent wiring type wherein disconnection and/or short circuit defects are reduced and a method for manufacturing the same. The liquid crystal display has one or a plurality of first electrodes within each pixel region, for forming one or a plurality of auxiliary capacitors in conjunction with the opposing pixel electrode. The first electrodes surround the pixel electrodes in a ring type structure, and are connected to each other between adjacent pixel portions by at least one wiring connecting portion. The first electrodes are driven independently from the scanning signal lines and the display signal lines. Forming the first electrodes of the capacitors as independent wiring type having a ring structure simplifies the manufacturing process and utilizes the maximum pixel area. Also, the degree of freedom concerning the selection of the driving pulse signal of the liquid crystal display is improved to reduce the R-C delay.

The present invention relates to a liquid crystal display and a method for manufacturing the same, and more particularly to an active matrix liquid crystal display wherein the display characteristics thereof are improved by an increase in the aperture ratio and a reduction of the capacitance of the gate wiring, and to a method for manufacturing the same.
The present invention is an improvement over the invention which is the subject matter of the present inventors' U.S. Pat. No. 5,517,341 which was filed on Jun. 1, 1993, the disclosure of which is hereby incorporated into this application by reference.
In response to a demand for personalized, space-saving displays which serve as the interface between humans and computers (and other types of computerized devices), various types of flat screen or flat panel displays, such as a liquid crystal display (LCD), a plasma display panel (PDP), an electroluminescent (EL) display, etc., have been developed to replace conventional display devices, particularly a cathode-ray tube (CRT) which is relatively large and obtrusive. Among these flat panel display types, the progress of LCD technology attracts the most interest. In some forms, LCDs match or surpass the color picture quality of CRTs.
Liquid crystal displays can have a simple matrix form or an active matrix form, using an electro-optic property of the liquid crystal whose molecular arrangement is varied according to an electric field. In particular, the LCD in the active matrix form utilizes a combination of liquid crystal technology and semiconductor technology, and is recognized as being superior to CRT displays.
The active matrix LCDs utilize an active device having a non-linear characteristic in each of a plurality of pixels arranged in a matrix configuration, using the switching characteristic of the device to thereby control each pixel. One type of the active matrix LCD embodies a memory function through an electro-optic effect of the liquid crystal. A thin film transistor (hereinafter referred to as a "TFT") having three terminals is ordinarily used as the active device, or a thin film diode (TFD), for example, a metal insulator metal type (MIM) having two terminals, is used. In the active matrix LCD which utilizes such active devices, millions or even billions of pixels are integrated on a glass substrate together with pixel address wiring, to thereby provide a matrix driver circuit, with the TFTs serving as switching elements.
However, in the active matrix LCD whose display has a large screen and high definition, the number of the pixels increases. Accordingly, the aperture ratio of the individual pixels is decreased, thereby concomitantly reducing the brightness of the LCD.
In the meantime, in the above active matrix LCD, a capacitance (Cgd) results between the gate and drain electrode of the TFT. When the signal of the gate pulse is changed from "High" to "Low", the potential of the pixel electrode is lowered due to the effect of the above capacitance Cgd. This lowering potential change is conventionally referred to as "offset voltage". When the offset voltage is applied to the liquid crystal as a direct voltage, an unfavorable phenomenon such as image sticking, flicker generation etc., occurs. Therefore, reducing such an offset voltage is necessary, as by forming an auxiliary capacitor in parallel with the liquid crystal cell.
Further, to obtain uniformity of an image displayed on the active matrix LCD, it is necessary that the voltage of a first signal applied through a data line in a writing operation is held constant for a certain time until a second signal is received. Also, in order to improve the image quality of the display, an auxiliary capacitor is formed in parallel with a liquid crystal cell. When the writing operation to the LCD is performed at a frequency of 60 Hz, the retaining duration is 16.7 milliseconds. The time constant, which is determined by the resistance of the liquid crystal and the dielectric constant thereof, must be sufficiently large with respect to the above values.
The auxiliary capacitor in parallel with the liquid crystal cell may be formed in two ways; that is, as an additional-capacitance type (Ca type) cell or as a storage capacitance type (Cs type) cell.
FIG. 1 shows a pixel layout of a conventional liquid crystal display on which the additional capacitance type storage capacitor is formed and FIG. 2 is a cross-sectional view taken along line II--II of FIG. 1.
In FIG. 1, a single pixel region and portions of adjacent pixel regions surrounding it, are illustrated. In a complete LCD display, rows of a number of gate lines 1 and orthogonal columns of a number of data lines 5a are arranged in a matrix configuration. Thus, a pixel is formed in the regions bounded by these two kinds of lines. In each pixel region, an additional-capacitance type capacitor Ca, a thin film transistor (TFT) as a switching device, a light transmissive portion (aperture area), a transparent pixel electrode 4 and a color filter layer 21 are provided. Gate line 1 and data line 5a are referred to as a scanning signal line and a display signal line, respectively.
As can be seen in FIG. 1, the first electrode 10 of each additional-capacitance type capacitor Ca is formed as a tab-like portion projected into a respective pixel portion from the scanning signal lines 1. Similarly, the gate electrode G of each TFT is also formed as an integral tab-like portion projected into a respective pixel portion from the scanning signal lines 1 (in the opposite direction to the corresponding first electrode of the capacitor). Each TFT system comprises a semiconductor layer 3 formed over a gate electrode G, a tab-like perpendicularly protruding portion of display signal line 5a (drain electrode) adjoining the left end of semiconductor layer 3, a source electrode 5b adjoining the right end of semiconductor layer 3 and a transparent pixel electrode 4. Transparent pixel electrode 4 is comprised of a transparent conductive material such as indium tin oxide (ITO).
All of the scanning signal lines 1, display signal lines 5a, capacitors Ca, TFTs, and pixel electrodes 4 are formed as part of a multilayer structure formed on the inner surface of a rear glass substrate 100, as can be seen in FIG. 2.
The process for forming the LCD having the additional-capacitance type capacitors Ca is explained in more detail as follows. First electrode 10 of each auxiliary capacitor Ca and each scanning signal line 1 are simultaneously formed by appropriately patterning an opaque conductive material (e.g., of aluminum, chromium, molybdenum, or tantalum) deposited on the inner surface of the rear glass substrate 100 via a conventional photolithography process. Thereafter, an insulating layer 2 is formed over the scanning signal lines 1, first electrodes 10 of capacitors Ca and the exposed regions of the inner surface of the rear glass substrate 100 as shown in FIG. 2. Next, the display signal lines 5a and transparent pixel electrodes 4 are separately formed, e.g., by successive photolithography processes. Then, a protective layer 6 is formed over pixel electrodes 4, display signal lines 5a, and the exposed regions of insulating layer 2, to thereby complete the multilayer structure provided on the inner surface of the rear glass substrate 100.
With reference to FIG. 2, the prior art active matrix LCD further includes a front glass substrate 101 having a multilayer structure formed on the inner surface thereof, and oriented parallel to the rear glass substrate 100. For example, a light shielding layer (black) matrix 20 for light shielding is formed on the inner surface of front glass substrate 101. Light shielding layer matrix 20 is formed by appropriately patterning a light-shielding layer via a conventional photolithography process, to define an aperture area occupying most of each pixel electrode 4 arranged on rear glass substrate 100. Thereafter, a color filter layer 21 is formed over light shielding layer matrix 20 and the exposed areas of the inner surface of the front glass substrate 101. The color filter layer 21 includes light transmissive portions 21a disposed in the aperture areas. Next, a protective layer 22 is formed over the color filter layer 21. Then, a transparent electrode 23 is formed over protective layer 22, to thereby complete the multilayer structure provided on the inner surface of the front glass substrate 101.
It can be noted that the conventional active matrix LCD further includes a thin layer of liquid crystal sandwiched between the front glass substrate 101 and the rear glass substrate 100, and disposed in contact with transparent electrode 23 and protective layer 6. Subsequent process steps well-known to those of ordinary skill in the pertinent art are then carried out to fix front glass substrate 101 and rear glass substrate 100 using a conventional sealant (not shown), and the liquid crystal is injected and sealed within the cavity formed therebetween.
In the active matrix LCD of the additional capacitance type, since first electrodes 10 of the additional-capacitance type capacitors and scanning signal lines 1 are simultaneously patterned using the same material, an additional process is unnecessary. Accordingly, the process for making the active matrix LCD can be simplified.
However, based upon the foregoing description of the conventional active matrix LCD, it should also be appreciated that the prior art suffers from certain drawbacks, as follows. Because the first electrode 10 of each capacitor Ca is formed of an opaque metal, and further, because the first electrode 10 of each capacitor Ca overlaps a significant portion of its associated pixel electrode 4, the aperture area of each pixel is significantly reduced by the corresponding overlap area, thereby reducing the aperture ratio thereof.
Moreover, since the display signal lines 5a and pixel electrodes 4 are formed together on the same insulating layer 2, they must be separated by a predetermined distance so as to achieve electrical isolation therebetween. This reduces the aperture area of the LCD and thus lowers the contrast ratio and luminance of the LCD.
Additionally, since the first electrode 10 of the additional capacitance is connected to the scanning signal line 1, i.e. the gate line, the wiring capacitance of the scanning signal line is greatly increased. Therefore, the load is increased when operating the scanning signal line, to increase the propagation delay time of the gate pulse signal, i.e. the gate delay.
FIG. 3 is an equivalent circuit diagram of the LCD device of the conventional additional-capacitance type as shown in FIGS. 1 and 2. In the unit pixel area defined by the scanning signal line 1 and the display signal line 5a, there exist capacitances such as the capacitance (Ccr) formed at the crossing portion of the scanning signal line 1 and the display signal line 5a, the capacitance (Cadd) formed between the pixel electrode 4 and the first electrode 10 of the additional-capacitance type capacitor Ca, the capacitance (Clc) formed between the pixel electrode 4 and the liquid crystal, the capacitance (Cds) formed between the source and drain electrodes of the thin film transistor, the capacitance (Cgs) formed between the gate and source electrodes and the capacitance (Cgd) formed between the gate and drain electrodes.
FIG. 4 is a layout of a pixel of a liquid crystal display which has an independent wiring type storage capacitance type capacitor Cs formed in parallel with the liquid crystal cell, as another prior art method for forming the auxiliary capacitor. FIG. 5 is a cross-sectional view taken along line IV--IV of FIG. 4, and shows only the lower part of the liquid crystal display panel. Here, like reference numerals as those of FIG. 1 and FIG. 2 represent the same elements.
There has been proposed an active matrix LCD of the storage capacitance type which has an additional light shielding layer which reduces the light leakage and has an independent wiring type storage capacitor so as to improve the characteristics of a display (see "High-Resolution 10.3-in Diagonal Multicolor TFT-LCD," M. Tsumura, M. Kitajima, K. Funahata et al., SID 91 DIGEST, pp. 215-218).
In the active matrix LCD disclosed in the above paper, in order to obtain a high contrast ratio and high aperture ratio, a double light shielding layer structure is formed and the storage capacitor is formed by an independent wiring separately formed apart from the gate line, so as to improve the display characteristics of the LCD.
In the structure of the above double light shielding layer, a first light shielding layer is formed on a front glass substrate on which a color filter is provided as in the prior art, and a second light shielding layer is formed on a rear glass substrate on which the TFT is provided. The LCD having such a double light shielding layer structure exhibits an aperture ratio which is improved by 6-20% over the conventional LCD having only the first light shielding layer. Also, the storage capacitor utilizes a common electrode with the gate electrode formed of aluminum whose resistance is only one-tenth that of chromium (Cr). Thereby, the propagation delay characteristics along the scanning signal line is improved.
The LCD having the double light shielding layer structure and the aluminum common electrode still needs much improvement. Also, there is undesirable a reduction of the aperture ratio due to the usage of an opaque metal (aluminum) for forming the electrodes of the storage capacitor associated with each pixel.
Moreover, the process for fabricating the second light shielding layer entails installing a light shielding layer before forming an insulating layer merely for shielding light during the manufacturing of the TFTs, thereby necessitating additional process steps which unduly increase the cost and complexity of the LCD manufacturing process.
As shown in FIG. 4, an independent wiring storage capacitance type capacitor Cs is a structure wherein a transparent, conductive material such as indium-tin oxide (ITO) replaces the opaque metal, e.g., the aluminum, in the above-mentioned conventional TFT-LCD. The light shielding layer structure formed around transparent pixel electrode 4 is not illustrated in FIG. 4 because it is not essential. FIG. 4 shows only part of a large number of pixel portions defined by a large number of scanning signal lines 1 and a large number of display signal lines 5a as shown in FIG. 1. Independent wiring storage capacitance type capacitor Cst is separated from scanning signal lines 1, differently from the additional capacitance type capacitor Ca shown in FIG. 1, so as to be connected with the capacitor Cs in the adjacent pixel portion by an independent wiring 11 formed as a different conductive layer.
As shown in FIG. 4, the LCD having the independent wiring storage capacitance type capacitor utilizes the inversely staggered TFTs as switching devices. If the forming process is observed, each gate electrode G which is formed such that each of scanning signal lines 1 is formed with a tab-like portion projected into each pixel portion, each first electrode 10a of each storage capacitor Cs and each independent wiring 11 which is an extension of the first electrode 10a are formed so as to be parallel to the rear glass substrate of the liquid crystal display panel. Successively, after insulating layer 2 such as with a silicon nitride (SiN) layer is formed on the front surface, a semiconductor layer 3 and a transparent pixel electrode 4 are formed in a predetermined pattern, and then the display signal lines 5a and the source electrodes 5b are formed thereon. Subsequent processes are accomplished by a method conventionally used in the LCD field.
Since the liquid crystal display of the independent wiring storage capacitance type capacitor as shown in FIGS. 4 and 5 utilizes transparent ITO for forming first electrode 10a of storage capacitor Cs, the aperture area does not decrease by as much as that of the opaque electrode type. Meanwhile, since the light shielding layer does not exist on the rear glass substrate of the liquid crystal display panel alongside the pixel electrode, the contrast ratio of the LCD is reduced significantly and an additional process is required for forming first electrodes 10a of storage capacitors Cs. (This process is performed by depositing an additional transparent conductive material such as ITO which is different from the opaque conductive material of the scanning signal lines and then etching the transparent conductive material.) Moreover, the manufacturing yield thereof is disadvantageous since the crossing portions of the wirings are increased when compared to the LCD as shown in FIG. 1.
FIG. 6 is an equivalent circuit diagram of the LCD device of the conventional auxiliary capacitor type as shown in FIGS. 4 and 5. In the unit pixel defined by the scanning signal line 1 and the display signal line 5a, there exist capacitances such as the capacitance (Ccr) formed at the crossing portion of the scanning signal line 1 and the display signal line 5a, the capacitance (Cst) formed between the pixel electrode 4 and the first electrode 10a of the opposing storage capacitor Cs, the capacitance (Clc) formed between the pixel electrode 4 and the liquid crystal, the capacitance (Cds) formed between the source and drain electrodes of the thin film transistor, the capacitance (Cgs) formed between the gate and source electrodes and the capacitance (Cgd) formed between the gate and drain electrodes.
In the LCD of the independent wiring storage capacitance type as shown in FIGS. 4 to 6, the capacitance of the gate wiring (Cin) may be calculated by the following equation (1). EQU Cin=Ccr+Cgs+1/[(1/Cgd)+{1/(Clc+Cst)}] (1)
In the meantime, in the LCD of the additional capacitance type as shown in FIGS. 1 to 3, the capacitance of the gate wiring (Cad) may be calculated by the following equation (2). EQU Cad=Cin+1/[(1/Cst)+{1/(Clc+Cgs)}] (2)
From the comparison of the above equations (1) and (2), the gate line capacitance of an additional capacitance type LCD is several times as much as that of a storage capacitance type LCD. Therefore, when operating the gate line of the additional capacitance type LCD, the load thereof is increased, which increases the gate delay.
From the above, although the manufacturing process of the additional capacitance type LCD is simplified, obtaining a uniform image is difficult due to the gate delay since the gate wiring capacitance is large. In the meantime, the gate wiring capacitance of the storage capacitance type LCD is small. However, forming the first electrode of the storage capacitor using an opaque metal, which simplifies the manufacturing process thereof, also lowers the aperture ratio significantly. Forming the first electrode of the storage capacitor using a transparent material improves the aperture ratio, but necessitates an additional process. Both the auxiliary capacitor type LCDs have many crossing points of the wiring layers, which increases the possibilities for discontinuity defects or short circuiting of the wiring.
To improve the problems exhibited in the above-mentioned liquid crystal display of the additional capacitance type (FIGS. 1 to 3) and in that of the independent wiring storage capacitance type (FIGS. 4 to 6), S. S. Kim et. al (including one of the present inventors) have described an invention wherein the LCD includes a storage capacitance type capacitor structured with a ring electrode which faces a corresponding transparent pixel electrode and encloses the transparent pixel electrode in a ring, as filed on Aug. 25, 1992 as U.S. patent application Ser. No. 07/934,396 which is now U.S. Pat. No. 5,339,181.
The LCD disclosed in U.S. Pat. No. 5,339,181 will be explained below with reference to FIGS. 7 and 8. Here, the same reference numerals as those of FIGS. 1, 2, 4 and 5 represent the same components.
As can be seen from a comparison of FIG. 7 with FIGS. 1 and 4, the active matrix LCD shown in FIG. 7 is manufactured according to the conventional method except for the fact that the layout of first electrodes 10 of storage capacitors (i.e. storage capacitance type capacitors) Cs associated with each pixel electrode 4 is changed so that the first electrode 10 is arranged in the peripheral region of the pixel electrode 4 to thereby increase the aperture ratio and contrast ratio of the LCD as compared with the conventional LCD. In more detail, the opaque metal layer from which the display signal lines 5a and the first electrodes 10 of storage capacitors Cs are formed is patterned in a manner such that the first electrodes 10 of storage capacitors Cs substantially surround their associated pixel electrodes 4, and preferably, overlap (i.e., underlay) only a peripheral edge portion thereof. As can be seen more clearly in FIG. 8 (taken along line VI--VI of FIG. 7), the first electrode 10 of the capacitor Cs is disposed substantially beneath the matrix of the light shielding layer 20 provided on the inner surface of the front glass substrate 101, and does not extend into the envelope of the aperture area, thereby significantly increasing the aperture ratio compared with conventional active matrix LCDs.
Additionally, the first electrode 10 of each capacitor Cs formed along the periphery of each corresponding pixel electrode 4, serves as an additional light shielding layer, as illustrated in FIG. 8. That is, the first electrode 10 minimizes the amount of leakage light passing through the aperture area of the front glass substrate 101 from the region of the liquid crystal located outside of the envelope of the aperture area.
In the case of the conventional active matrix LCD depicted in FIG. 2, it can be seen that any extraneous light entering the front glass substrate 101 at an angle of incidence greater than .THETA..sub.1 is emitted through the aperture area of the front glass substrate 101. In the case of the LCD of U.S. Pat. No. 5,339,181, only extraneous light which enters the front glass substrate at an angle of incidence greater than .THETA..sub.2 is emitted through the aperture area of the front glass substrate as illustrated in FIG. 8. Excess light (or "leakage light") which strikes the front glass substrate whose angle is less than the angle of incidence .THETA..sub.2 is blocked by first electrode 10 of the adjacent storage capacitor. Thus, relative to the aforesaid prior art active matrix LCDs, the LCD of the U.S. Pat. No. 5,339,181 reduces the amount of leakage light emitted through the aperture area of front glass substrate 101 by an amount which is proportional to the difference between .THETA..sub.2 and .THETA..sub.1, thereby significantly increasing the contrast ratio.
Meanwhile, the liquid crystal display having the ring type electrode storage capacitor represents an improvement in display characteristics, i.e., a better aperture ratio, increased contrast ratio, etc. However, due to the introduction of foreign matter or in case of a weak insulating film at wiring crossings (the intersection of scanning signal lines 1 and display signal lines 5a), wiring fractures in scanning signal lines 1 and/or short circuits between scanning signal lines 1 and display signal lines 5a may occur, to thereby significantly lower the yield of manufactured liquid crystal displays.
In order to solve the problems of wiring fractures in scanning signal lines 1 and/or short circuits between scanning signal lines 1 and display signal lines 5a without reducing the aperture ratio and the contrast ratio, U.S. Pat. No. 5,517,341 describes an invention wherein each row of adjacent first electrodes of the capacitors are electrically connected together using redundancy connecting conductors or wherein the LCD has duplicated scanning signal lines associated with each pixel and electrically connected to the first electrode of the capacitor.
FIG. 9 shows a pixel layout of a liquid crystal display according to one embodiment of the invention disclosed in the above U.S. Pat. No. 5,517,341. Here, the same reference numerals as those of FIGS. 1 to 8 represent the same components.
Referring to FIG. 9, the liquid crystal display is the same as that having a ring-structured capacitor electrode as shown in FIG. 7 except that a redundancy connecting portion 12 is formed between the first electrodes 10 of the storage capacitors which are formed in each pixel region in a manner such that the first electrodes 10 of storage capacitors Cs substantially surround their associated pixel electrodes 4. Redundancy connecting portions 12 which are connected between the first electrode 10 of each one of the storage capacitors are simultaneously formed with a pattern of the first electrodes 10 and intersects display signal lines 5a with a dielectric film interposed therebetween.
FIG. 10 shows a pixel layout of a liquid crystal display according to another embodiment of the invention disclosed in the above U.S. Pat. No. 5,517,341. Here, the same reference numerals as those of FIGS. 1 to 8 represent the same components.
Referring to FIG. 10, the liquid crystal display is the same as that having a ring-structured capacitor electrode as shown in FIG. 7. The liquid crystal display shown in FIG. 10 is characterized by having its scanning signal lines duplicated as first scanning signal lines 1a and second scanning signal lines 1b as compared with the pixel layout of the liquid crystal display shown in FIG. 7 as described above. A plurality of the scanning signal lines which are each constituted by an electrode pair of a first scanning signal line 1a and a second scanning signal line 1b are arranged at predetermined intervals. Here, the pixel portions are defined within first and second scanning signal lines 1a and 1b and display signal lines 5a.
Moreover, as compared with FIG. 7, the thin film transistor TFT, employed as a switching device, is not formed on an integral protruding tab-like portion of a corresponding scanning signal line 1 but rather is formed on first scanning signal line 1a. That is, a gate electrode of the thin film transistor is rotated 90.degree. so as to be consistent with first scanning signal line 1a, thereby to maximize the aperture ratio of the liquid crystal display.
In the above liquid crystal display as shown in FIGS. 9 and 10, the redundancy connecting portions for connecting the first electrodes of the capacitors or the two-fold scanning signal lines are formed by a simple change of the pattern layout without requiring an additional process. The first electrode is formed to be a ring-type which can utilize a maximum pixel area, thereby enhancing the aperture ratio of the LCD. Since the first electrode of the storage capacitor serves as an additional light shielding layer, the contrast ratio is greatly enhanced.
Additionally, a redundancy connecting portion is formed for connecting the first electrodes of the capacitors to each other, or the scanning signal lines are doubled, so that disconnection and shorting defects of the scanning signal lines in the crossing portions of the wirings can be decreased and repaired. For example, referring to FIG. 10, a disconnection defects occurs with respect to one display signal electrode 5a when disconnections occur at the crossing portions with of first and second scanning signal electrodes 1a and 1b, but not when a disconnection occurs either with first scanning signal electrode 1a or with second scanning signal electrode 1b. In the meantime, when a short circuit occurs between either of the scanning signal electrodes 1a and 1b and the display signal electrode 5a, the shorting defects may be repaired by cutting the signal line on both sides of the crossing portion where the short circuit has occurred. Since the scanning signal electrode is duplicated, the shorting defect may be easily repaired.

Liquid crystal display and a method for manufacturing the same


An apparatus used in the manufacture of a thermoplastic zipper having a slider mounted thereon includes a pair of clamp arms disposed on opposing sides of a path of the zipper. The clamp arms are movable in directions substantially perpendicular to the zipper path so as to clamp the thermoplastic zipper to fuse a length thereof. A pair of fingers is disposed on opposing sides of the zipper path. The fingers are movable in directions substantially perpendicular to the zipper path and in directions substantially parallel with the zipper path relative to the clamp arms. The fingers push the slider along the zipper.

1. Technical Field
This invention relates generally to an apparatus for and method of moving a slider mounted on mating zipper elements during the production of plastic bags or the like, and in particular to an apparatus for and method of fusing a length of the mating zipper elements and positioning the slider with respect to the fused length.
2. Background Art
The manufacture of thermoplastic bags and the like containing mating zipper elements (i.e., a thermoplastic zipper typically having a rib and groove construction) that are operated by a slider mounted thereon are known in the art. There are a wide variety of designs for such devices. For example, U.S. Pat. Nos. 5,067,208; 4,262,395; and 5,283,932, show different types of sliders and mating zipper elements used in the construction of re-sealable thermoplastic bags. In these and other known arrangements, the sliders operate to connect and disconnect (depending on the direction of movement) opposing mating zipper elements (i.e., an opposing rib and groove) as the slider is moved along the length of the zipper by a user. Thus, by moving the slider, the user can open or close the re-sealable thermoplastic bag or other such product.
In the manufacture of such thermoplastic bags, for example, a web of folded thermoplastic film is used to form a series of bags. Formed on ends of the folded thermoplastic film opposite the fold are corresponding mating zipper elements. As the film is fed along different stages of the manufacturing process, various assemblies perform tasks such as mounting the sliders on the zippers corresponding to separate bags, severing and sealing the film in directions perpendicular to the fold to form the lateral edges of the separate bags, and fusing specified lengths of the mating zipper elements to form the ends thereof for separate bags.
In a typical manufacturing process, the thermoplastic film is indexed to a registered position (i.e., one stage of manufacturing) at which movement of the film is halted while individual components perform different manufacturing processes, such as those described above. At some stages, it may be necessary to move the slider along the mating zipper elements so that it does not interfere with certain processes, or so that the slider is properly positioned for packaging and shipping.
For instance, one stage of the manufacturing process will typically include clamp/stomp members that clamp/stomp a length of the mating zipper elements to meld or crush the elements together to define the ends of the zippers of different bags. Typically, such stomp members are heated so as to fuse the mating zipper elements. It is preferable to move the slider along the zipper after fusion so as to move the slider to a predetermine position along the mating zipper elements.
In one known system for positioning the sliders as described above, the thermoplastic film is indexed to a registered position at which heated stomp members fuse a length of the mating zipper elements. As the fused length is then indexed to the next stage in the manufacturing process, a projection is brought into range of the thermoplastic film such that the projection does not interfere with the movement of the film, but prevents a corresponding slider from moving in the path of the film. This causes the slider to remain still as the film is indexed. The movement of the slider along the mating zipper elements connects/closes the mating zipper elements. Once the film has moved with respect to the slider and projection such that the slider comes into contact with a corresponding fused length of the mating zipper elements, the projection is brought out of contact with the slider. Consequently, the slider is positioned at a predetermined position along the mating zipper elements relative to the fused length of the zipper elements, and resumes movement in the film path.
Of course, this projection arrangement can be used in conjunction with other stages of manufacturing to position the slider for other reasons. For instance, the slider may be moved so as to not interfere with other components of the manufacturing process that act on the film.
However, use of the movable projection discussed above has several drawbacks. In particular, because the projection is operated separately from the apparatus for fusing the mating zipper elements (or other component of the manufacturing process) the timing between the two systems can become out of sync. This in turn leads to incorrect positioning of the slider.
In addition, when the indexing speed of the film is increased, the reliability of the movable projection for precisely positioning the slider degrades. Specifically, at increased manufacturing speeds, the positioning of the projection must take place within a smaller window of time because the point along the mating zipper elements to which the slider must be moved approaches more quickly. Accordingly, small timing errors are magnified at faster operating speeds.
Such inaccuracies can lead to the projection not releasing from the slider in time, causing the slider to move past the intended position or, when the slider is to abut a fused length of the zipper, to catch on the fused portion and build up tension in the moving film. Also, when the slider is being moved to close the mating zipper elements, if the projection releases its contact with the slider too soon or fails to catch the slider at all, the slider may not be moved to the predetermined position relative to the fused length of the zipper.
These problems become even more apparent in modern manufacturing processes in which the film is not indexed between stages, but instead is continually fed through the manufacturing system. In such systems, the film is continually moved along the manufacturing path as movable apparatuses for performing certain manufacturing steps are moved therewith at the same rate. The different apparatuses are typically moved along a rotating path so that they come into contact with the film at given intervals.
For instance, the stomp members may be provided on a rotating belt such that the stomp members move along the film path for a set interval at the same rate of speed as the film (see FIG. 6 and the accompanying text below). Accordingly, the stomp members may stomp and fuse the mating zipper elements as the film and stomp members move together along the film path. Such a manufacturing process allows for much faster run times.
Therefore, not only is there a need for a mechanism to accurately position the sliders in assembly lines running at higher rates of speed, but there is also a need for positioning mechanisms that can operate in continuous movement systems, in conjunction with movable assembly stages such as the moving stomp members discussed above.

Apparatus for and method of positioning a slider on mating zipper elements


An electrical machine has a stator, and a rotor defining an axis of rotation, the stator including laminations located along that axis, the laminations having protrusions, the protrusions on each lamination being circularly spaced apart about the axis to define cooling air flow passages, and a fan mounted on the rotor to effect flow of cooling air into and through such passages as the rotor rotates.

This invention relates generally to the cooling of electrical machinery, and more particularly to obtaining more efficient heat transfer from laminations used in the stators and rotors of such machinery.
Cooling of electrical machines becomes more difficult when the sizes of stators and rotors is reduced while power handling remains the same, or is not proportionally reduced. There is need for improvements in heat transfer usable in stators and/or rotors, to meet cooling requirements.
This invention represents an improvement with respect to that disclosed in U.S. Pat. No. 5,491,371.


The object is to provide a showcase having a connection device which can improve the workability in connection of adjacent showcases and can improve the appearance. The showcase has a connection device for connection of the show case with another adjacent showcase at one side of the lower retreating section of the front wall of the insulating wall, wherein the features are: the connection device includes a receiving metal fixed to the retreating section and a connecting metal extending over and mounted on the receiving metal and a receiving metal of another adjacent showcase; and the receiving metal has a mounting surface positioned on the front side of the retreating section and directed forward, and the mounting surface has a mounting hole formed for securing the connecting metal thereto.

Conventionally, a plurality of showcases having respective display rooms therein are placed side by side in shops such as supermarkets and used for display and sale of foods and other goods. In general, in the case where several showcases are arranged side by side, side plates are not used at the adjacent ends of the adjacent showcases and the adjacent ends are directly brought into abutment against each other at the installation site, so that the display rooms in the showcases communicate with each other and constitute a single continuous display room, in order to provide feeling of unity of the display of goods in the respective display rooms (Refer to Japanese Patent Laid-open Publication No. 5-305019, for example).
Now, referring to FIGS. 9 and 10, the connection structure of a conventional showcase is explained. A heat insulating wall 100 constituting a body of the showcase is formed in a substantially falling U-shape in cross section, with a front opening, a lower front wall 101 of the heat insulating wall has a lower retreating section 102, and the lower end of the retreating section 102 continues to the front end of a bottom wall 103 of the heat insulation wall 100. A connecting member 105, which has a substantially L-shape in cross section, is fixed to the retreating section 102 and is brought into abutment against the connecting member 105 mounted on another showcase adjacently installed, these connecting members 105 being mutually connected together by inserting bolts through the connecting members 105 and screwing nuts on the bolts.
In addition, bumpers 106 are provided at the fronts of these retreating sections 102 in order to protect the showcases from collision of carts or the like used in the shop. To connect the bumpers 106 at the connection section of the adjacent showcases, a bumper connecting member 107, which has a substantially falling U-shape in cross section, with a front surface extending substantially perpendicularly, is mounted on the front of the retreating section 102. The bumpers 106 are mounted on the showcases with their ends put together, and a bumper connection cover 108 is applied to the front of the connection section of these bumpers 106. The bumper connection cover 108 is fixed to the bumper connection member 107 with screws. Thus, the connection section of the bumpers 106 is covered with the bumper connection cover 108.
In addition a handrail 110 is provided longitudinally at the top of the lower front wall 101 of the heat insulating wall 100. At the connection section of the adjacent showcases, a handrail connection cover 111 is mounted to cover these handrails 110.
Because the connecting member 105 as described above is mounted on the retreating section 102 which is a recessed section of the lower part of the front wall 101, it has been difficult to connect it with another connecting member 105. In addition, because these connecting members 105 are brought into abutment against each other and fixed with bolts and nuts, it has been necessary to perform operations in such a manner that the showcases are arranged so that the front walls of the heat insulating walls 100 become flush with each other in advance and then to bring the connecting members 105 and 105 into abutment against each other.
However, since the showcases are large by themselves, it has been difficult to finely align large showcases, and it has been actually difficult to set the connecting members 105 of the showcases exactly flush with each other. In the case where other showcases are laid out on both ends of a showcase, in particular, alignment is required at both ends and it is quite difficult to set the front walls of all showcases flush with each other.
Therefore, the showcases are connected using connecting members 105 screwed by bolts and nuts, with buffering some errors. At the surfaces where the showcases are put together or the section where the bumpers or handrails are put together, some gap may be generated. It is thus necessary to conceal such gap, and the bumper connection cover 108 and the handrail connection cover 111 are provided.
However, existence of the bumper connection cover 108 and the handrail connection cover 111 hampers feeling of unity of the showcases laid out adjacently, and they are not preferable from the viewpoint of appearance. Since the handrail connection cover 111, in particular, is formed so that it protrudes above the handrail 110, dust or other wastes are easily deposited on the handrail connection cover 111, and it is difficult to clean there, so there is a problem from the viewpoint of hygiene. Furthermore, because such covers easily catch the customers' or workers' cuff or the like, it is requested from the market to remove these connection covers.
The present invention has been made to solve the conventional technical problems, and it is an object of the present invention to provide a showcase which can improve the connection workability for adjacent showcases and is provided with a connection device enabling improvement of the appearance.