Abstract:
A vacuum container comprising: a first and second substrate of relatively the same dimensions and areas, a peripheral seal positioned about the outer periphery of each substrate for bonding the first substrate to the second substrate to form a composite stacked member; and a getter box having a vacuum aperture in one side with an evacuation tube of a given diameter opening to enclose the vacuum aperture, the tube joined to the box about the opening and having a sealed end remote from the box, the getter box having a getter source in the box hollow to absorb any residual gasses in the display hollow after the display hollow has been evacuated to a desired vacuum before sealing the end of the evacuation tube, wherein the area of the aperture is equal to or greater than π(D/2) 2  where D is the diameter of the evacuation tube opening.

Description:
FIELD OF THE INVENTION  
       [0001]    This application relates to a hermetically sealed flat panel display maintained at a high vacuum utilizing a getter enclosed in a low profile containment. 
       BACKGROUND OF THE INVENTION  
       [0002]    Flat panel display (FPD) technology is one of the fastest growing display technologies in the world, with a potential to surpass and replace cathode ray tubes (CRTs) in the near future. As a result of this growth, a large variety of FPDs exist, which range from very small virtual reality eye tools to large hang-on-the-wall television displays. 
         [0003]    The FPD generally includes a hermetically sealed vacuum container or envelope formed by sealing an anode substrate to a cathode substrate. A display employs phosphors at pixel locations which emit light when energized. 
         [0004]    The anode substrate and the cathode substrate of such displays are made of thin glass plates each having a thickness as small as, for example, between 0.5 to 2.5 millimeters (mm) and are spaced from each other at a distance as small as 0.2 mm, resulting in the envelope being highly reduced in thickness. The substrates are rectangular and each of the same size. The substrates can be any size. Viewing areas vary accordingly and can be used as automotive, telephone, computer and other displays requiring small (or large) size and high (or low) resolution and larger sizes for computer and television devices, for example. However, the attachment of devices to insure the evacuation of residual gases in the envelope often compromise the overall thickness of the construction. U.S. Pat. No. 6,084,344 (&#39;344 patent) issued on Jul. 4, 2000 to T. Kishino et al. and entitled “Reduced Thickness Vacuum Container With Getter” and assigned to Futaba Denshi Kogyo K.K. of Japan, describes prior art techniques used to evacuate such displays having anode and cathode substrates. The patent also describes a problem which is inherent in making thin displays. For example, as indicated above, such displays may have a spacing as small as 0.2 millimeters. The evacuation tube which goes to the evacuation pump has an inside diameter which is approximately 2 mm and an outside diameter of 4 mm. Therefore, since the evacuation tube has a diameter (outside) of 4 mm, one cannot easily evacuate the display via the thin bonded sides or the periphery, which sides are bonded by a glass frit joining the anode plate (or substrate) to the cathode plate. This cannot be done because of the fact that if the glass is, for example 0.7 mm in thickness, the entire display including the spacing is about 1.6 millimeters in thickness (0.7 mm cathode+0.7 mm anode+0.2 mm spacing). Therefore, the tube from the pump is of a diameter greater than the thickness of the display. The above-noted &#39;344 patent discloses a first series of solutions that involve putting a through-hole in the cathode or the anode substrate with no hole in the periphery. When placing a hole or aperture in the periphery of the display one had to extend the anode or cathode structure so that one could place a getter box over the display, which getter box as shown in  FIG. 8  and  FIG. 9  of the &#39;344 patent has an aperture including an internal cavity which contained a getter, and which getter box interfaced with the side surface of the display. In any event, in order to support the getter box, one had to extend either the cathode or the anode plates. This is clearly shown in  FIGS. 8 ,  9 ,  10  and  11  of the &#39;344 patent.  FIGS. 12 and 13  of the &#39;344 patent also show apertures in the periphery of the device, with the aperture communicating with the getter box, which again requires an extension of either the cathode or the anode. In that patent, the evacuation is always transverse to the cathode and anode plates thereby significantly increasing the thickness. In order to insure that the FPD functions reliably, the envelope formed by the anode and cathode must be evacuated of all gases. Typical evacuation is in a range between 10 −5  and 10 −6  Torr so that the displays emit electrons with great efficiency. However, one can see also from the above noted patent, this creates a problem and requires extending the anode or cathode substrate to accommodate the getter box. 
         [0005]    The present invention involves placing a getter box at the sides or periphery of the display, which getter box is attached to the periphery of the display without the need to extend the cathode or anode substrate. 
       SUMMARY OF THE INVENTION  
       [0006]    According to an aspect of the present invention, a vacuum container is formed from two substrates arranged opposite to each other, spaced from each other at a predetermined distance, and sealed about the periphery. A getter box is attached to the side of the display and a hole (e.g. rectangular) in the periphery of the display is surrounded by the getter box which has a separate aperture for communicating with the evacuation tube while enabling efficient exhaust. 
         [0007]    According to another aspect of the invention, a vacuum container comprises: a first and second substrate of relatively the same dimensions and areas, a peripheral seal positioned about the outer periphery of each substrate for bonding the first substrate to the second substrate to form a composite stacked member of a given height with the first substrate bonded to the second substrate with the seal sandwiched between the substrates, the substrates separated one from the other by the width of the seal to create an internal hollow between the substrates, the seal having an elongated aperture between the substrates, a getter box having a top and a bottom surface with a first and a second side joining the top and bottom surfaces, with a front opening of the box having a length greater than the length of the aperture and a width greater than the thickness of the composite member, the box joined to the substrates to cover and enclose the aperture in the seal, the box having a vacuum aperture in one side with an evacuation tube of a given diameter opening to enclose the vacuum aperture, the tube joined to the box about the opening and having a sealed end remote from the box, the getter box having a getter source in the box hollow to absorb any residual gasses in the display hollow after the display hollow has been evacuated to a desired vacuum before sealing the end of the evacuation tube, wherein the area of the aperture is equal to or greater than π(D/2) 2  where D is the diameter of the evacuation tube opening. 
         [0008]    In another aspect of the present invention, an FPD comprises a vacuum envelope formed from a cathode substrate and an anode substrate joined by one or more outer peripheral members that provide at least one access hole to a getter box, and an associated evacuation tube further including within the envelope a plurality of electrically addressable pixels; a plurality of thin-film transistor (TFT) driver circuits each being electrically coupled to an associated at least one of the pixels, respectively; a passivating layer on the thin-film transistor driver circuits and at least partially around the pixels; and, a cathode; wherein addressing one of the pixels using the associated driver circuit causes the cathode to emit electrons that induce the one of the pixels to emit light. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0009]    It is to be understood that the accompanying drawings are solely for purposes of illustrating the concepts of the invention and are not drawn to scale. The embodiments shown in the accompanying drawings, and described in the accompanying detailed description, are to be used as illustrative embodiments and should not be construed as the only manner of practicing the invention. 
           [0010]      FIG. 1   a  illustrates a perspective view of a display vacuum container showing the top substrates and side members according to an embodiment of the present invention; 
           [0011]      FIG. 1   b  illustrates a side view of a display device showing a getter box and evacuation tube according to an embodiment of the present invention; 
           [0012]      FIG. 1   c  illustrates a cross sectional view Al of a display device showing a getter box and evacuation tube according to an embodiment of the present invention; 
           [0013]      FIG. 2  illustrates a top view of a display device and a getter box and evacuation tube according to an embodiment of the present invention; 
           [0014]      FIG. 3   a  illustrates a perspective view of an exemplary getter box according to an embodiment of the present invention;  FIG. 3   b  shows a front view of the getter box of  FIG. 3   a.    
           [0015]      FIG. 4   a  illustrates a vacuum container and a getter box according to another embodiment of the present invention. 
           [0016]      FIG. 4   b  shows a perspective view of the getter box of  FIG. 4   a.    
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0017]    It is to be understood that the figures and descriptions of the present invention have been simplified to illustrate elements that are relevant for a clear understanding of the present invention, while eliminating, for the purpose of clarity, many other elements found in typical FPD systems and methods of making and using the same. Those of ordinary skill in the art may recognize that other elements and/or steps are desirable and/or required in implementing the present invention. However, because such elements and steps are well known in the art, and because they do not facilitate a better understanding of the present invention, a discussion of such elements and steps is not provided herein. 
         [0018]    Referring to  FIG. 1   a  there is shown a container which constitutes a display container and which container has to be evacuated. The container consists of a first substrate which is normally a glass sheet or plate  160  designated for purposes of explanation as an anode. The anode plate on the inner surface may contain suitable phosphors which can be arranged as fine dots or pixels. Sealed to the anode plate is a cathode substrate or glass plate  110 . As indicated, the cathode,  110 , may, for example, contain field emission devices or other devices to activate the phosphors on the anode. In one configuration the two glass substrates operate as anode/cathode substrates respectively for an FPD. In another configuration, such as a nanotube configuration, one of the glass substrates operates as the anode (i.e. no cathode configuration) while the other glass substrate is simply a viewing glass devoice of any components that operates to maintain the vacuum for the structure. Again, it is indicated that there are many types of flat panel displays which are known in the prior art. All such displays must be evacuated and therefore the spacing between the anode and cathode is at a high vacuum to enable efficient display operation. Also shown, is a spacing member  109 . Typically spacer  109  consists of a glass seal, which glass seal firmly spaces and separates the anode  110  from the cathode  160 . This spacing may be on the order of 0.2 millimeters. The thickness of the anode and cathode plates may vary from between about 0.5 mm to about 2.5 mm. For a preferred display the thickness of the anode substrate  110  and the cathode substrate  160  is about 0.7 mm. Therefore, with the spacing  109  of 0.2 mm, the entire thickness of the display designated by reference numeral x, is 1.6 millimeters. In order to insure that the FPD device functions as a display device, the interior of the envelope  100  which includes the anode substrate  160  and the cathode substrate  110  should be kept at a high vacuum. 
         [0019]    For example in the case of a low voltage phosphor display the vacuum permits the field emission cathode to emit electrons which impinge upon the anode at high efficiencies. Such a display should have a vacuum anywhere from 10 −5  Torr to 10 −6  Torr. Spacing  109  is on the order of 0.2 mm. An aperture  216  which is made on a peripheral portion of the display between the anode and the cathode is rectangular and is selected in accordance with the diameter of the evacuation tube. The dimension of the aperture  216  which as seen is rectangular in shape, is selected so that the evacuation pump in conjunction with the evacuation tube can operate to efficiently and quickly evacuate the space between the anode and cathode. Instead of aperture  216  a hole in the side would only be 0.2 mm in diameter. This diameter is unacceptable because of the fact that the exhaust mechanism which includes the exhaust tube cannot and will not be able to create a vacuum due to the small sized aperture. 
         [0020]      FIG. 1   b  shows the partial view of the anode substrate  110  which as indicated is a glass substrate. The cathode substrate  160  which is also a glass substrate is joined or sealed to the anode by spacer member  109  formed of a suitable adhesive such as a low melting glass or a glass frit or other suitable adhesive, which firmly seals the anode  110  to the cathode  160 . The aperture  216  is shown. The aperture  216  has a width which again is equal to the width of the spacer  109 , and as indicated is 0.2 mm. It also has a length L. The length L is selected as follows. A typical exhaust tube has an inner diameter of 2 mm. This inner diameter is specified because of the exhaust port associated with the exhaust motor which thereby draws air from the spacing in the envelope and produces a vacuum. The exhaust tube has an inner diameter of 2 mm with an outer diameter of 4 mm. The 2 mm diameter specifies an area of exhaust for proper operation. The area of exhaust equals πD 2 . Therefore, for an outer diameter of 2 millimeters, πD 2  is approximately equal to 12 square millimeters. Thus, the aperture  216  would have a length of 60 millimeters (0.2 mm×60 mm=12 sq. millimeters). This area of 12 square millimeters is provided by aperture  216  which therefore enables the pump to evacuate the spacing between the anode and cathode at the appropriate exhaust with the correct air flow. 
         [0021]      FIG. 1   c  illustrates a cross sectional view of one embodiment of the vacuum container  100  housing a TFT anode/cold cathode FPD according to an embodiment of the present invention. In this exemplary embodiment, the FPD includes cathode  104  positioned on the glass substrate  110 . The cathode acts as a low-voltage source of electrons. While not shown in this embodiment, it is nevertheless understood that both the cathode and anode may be on the same plate or substrate (such as for example in a nanotube emitter configuration). The glass anode substrate  160  employs TFT circuitry to control the attraction of electrons  140  emitted from the cathode  104 . As shown in  FIG. 1   a  and  FIG. 1   b  the glass anode substrate  160  and cathode substrate  110  are joined by frit glass side or spacer members  109 . The glass spacers are preferably each 0.2 mm thick. The anode and cathode substrates are large in area compared to the getter box and therefore broken lines  190  are employed to indicate that the length of the substrates are shown by way of example in  FIG. 1   c  but are relatively longer (as above indicated). Vacuum container  100  has an aperture or through-hole  216  formed in one of its side members. To provide the through-hole  216  on any side, the side member may be essentially split into two side member parts each of which is foreshortened to create the access hole in the gap between the members. In the embodiment illustrated in  FIG. 1   a  and  FIG. 1   b,  the through-hole  216  is formed between the anode substrate and the cathode substrate or on the short side between the side members. In  FIG. 1   c,  getter box  218  is then positioned and installed over the through-hole  216  which has a generally rectangular shape formed in the gap. As shown in  FIG. 1   b  the through-hole  206  in one example has dimensions of 0.2 mm×60 mm. In turn getter box  218  interfaces with the evacuation tube  212  through the access hole  216 . 
         [0022]    The evacuation tube  212  is cone-like in geometric shape. The cone shape of the evacuation tube  212  with the apex  220  is formed after the display envelope is evacuated. The evacuation tube has an inner diameter (A) of 2 mm and an outer diameter (B) of 4 mm. The tube is made of glass and is connected at one end to an evacuation pump (not shown). After evacuation to the desired vacuum (10 −5 -10 −6  Torr) the glass evacuation tube is heated and drawn closed by pulling and compressing as the glass becomes molten, hence forming the conical like shape. In the embodiment shown, the through-hole  216  is arranged at a left side end portion of the peripheral seal joining the glass members. It is recognized that the through-hole  216  may be formed on any one of the four sides of the vacuum container  100 . 
         [0023]    As indicated, the through-hole  216  functions as a port through which the gas (i.e., air) in container  100  is withdrawn under pressure from the external pump, through the evacuation tube  212  and discharged. After the pump has discharged the air content to a particular low level, the getter  214  (after activation) substantially absorbs the gas remaining in the container  100 . Getters are typically composed of materials of the non-vaporization type such as Ti-Zr-Al alloy, Ti-Zr-V—Fe alloy or any material of the vaporization type such as Ba—Al alloy. In each of the embodiments described herein, the getter  214  is arranged on a side of the getter box  218 . Multiple getters may be installed and arranged in the getter box  218  depending on the requirements for the particular FPD. Furthermore, the getter  214  may be formed into any suitable shape such as a pill-like cylinder, bar, or ring-like member, provided it can be housed in the getter box  218 . In  FIG. 1   c  for a typical display the width (w) of the aperture  216  is 0.2 mm. The dimension A which is the inner diameter of the evacuation tube is 2 mm. As seen the getter box and tube are joined together by glass frits. There is shown “L” shaped supports  219  and  220  which secure the evacuation tube to the sides of the getter box  218 . The outer diameter B of the evacuation tube as shown is 4 mm and therefore the wall thickness C is 1 mm. The thickness of the getter box walls D is 1 mm. Glass frit seals  221  and  222  secure the getter box to the anode and cathode substrates. Since all these components are glass, joining and sealing them, as shown, is easily implemented. The thickness of the space seals  221  and  222  (and corresponding glass frit) is based on the difference between the thickness of the display and the getter box width “A” ( FIG. 1   c ). 
         [0024]    Anode substrate  160  includes a plurality of conductive pads  170  fabricated in a matrix of substantially parallel rows and columns on substrate  160  using known fabrication methods. Column conductors  177  are associated with each of the corresponding conductive pads  170 . In this illustrated embodiment substrate  160  is a transparent material such as glass. Conductive pads  170  are also composed of a transparent material, such as Indium Titanium Oxide (ITO). The getter box  218  and the envelope  100  are also fabricated from a material such as glass. It is of course recognized that the pixels may range from opaque to transparent according to the desired application and/or viewing perspective. 
         [0025]    Deposited on each conductive pad  170  is phosphor layer  175 . Phosphor layer  175  may be selected from materials that emit light  195  of a specific color. In a conventional RGB display, phosphor layer  175  may be selected from materials that produce red light, green light or blue light  195  when struck by electrons  140 . As will be appreciated by those skilled in the art, the terms “light” and “photon” are used synonymously and interchangeably herein. A matrix organization of conductive pads and phosphor layers allows for X-Y addressing of each of the individual pixel elements in the display will be understood by one skilled in the pertinent arts. 
         [0026]    Associated with each conductive pad  170 /phosphor layer  175  pixel is a TFT circuit  180  and associated TFT final passivation layer  179 , that serve to apply a known voltage to the associated conductive pad  170 /phosphor layer  175  pixel. For example, TFT circuit  180  operates to apply either a first voltage to bias an associated pixel element to maintain it in an “off state or a second voltage to bias an associated pixel element to maintain it in an “on” state, or an intermediate state. In this illustrated case, conductive pad  170  is inhibited from attracting electrons  140  emitted by cathode  104  when in an “off” state, and attracts electrons  140  when in an “on” state or an intermediate state. 
         [0027]    The use of TFT circuitry  180  for biasing conductive pad  170  provides the dual function of addressing pixel elements and maintaining the pixel element in a condition to attract electrons for a desired time period, i.e. time-frame or sub-periods of a time-frame. Cathode  104  is fabricated by progressively depositing onto substrate  110 , conventionally a glass, an insulating material  115 , such as a silicon dioxide (SiO 2 ), an edge emitter material  120  operable to emit electrons, a second insulating layer  125 , such as SiO 2 , and a second conductive material  130 , such as Mo. Emitter material  120  may be selected from known materials that have a low work function for emitting electrons  140 . Emitter material  120  may comprise a metal such as Molybdenum (Mo), for example. Wells  136  are formed through the deposited second conductive layer  130 , insulating layer  125 , emitter layer  120 , and insulating layer  115  using well-known techniques, such as photo-etching. In this case, edges  135  of emitter material  120  are exposed and generate electrons  140  under excitation. Second conductive material  130  operates as a gate electrode to draw electrons  140  from the edges of emitter material  120  when a sufficient potential difference exists between conductive material  130  and emitter layer  120 . 
         [0028]      FIG. 2  illustrates a top view of the vacuum container  100  according to the present invention. As indicated through-hole  216  has a generally rectangular shape formed by the foreshortened sides and the top and bottom plates referred to as substrates  160  and  110  of the vacuum container  100 . In the illustrated embodiment, the through-hole  216  is installed at the top end portion of the container  100  to provide for communication between getter box  218  via through-hole  216  and the vacuum container  100 . The through-hole  216  has a width W of 0.2 mm and a length L which is greater than 60 mm, and preferably about 70 mm. The getter box  218  is placed over the (rectangular) hole  216  and sealed to the display as shown in  FIG. 1   c.  The getter box opening  420  ( FIG. 4A ) is much longer than it is wide. This enables the 2 mm internal diameter evacuation tube to completely and rapidly evacuate the container  100 . 
         [0029]    Referring to  FIGS. 3   a  and  3   b  there is shown a perspective view of a getter box  218  in  FIG. 3   a  and a front view of the box in  FIG. 3   b.  Essentially as shown in  FIG. 3a , the getter box comprises a rectangular box having a front opening. The box may be fabricated by the use of thin glass plates such as  300 ,  302 ,  303  and  304 . These plates may be joined together by glass frits or other well known techniques. In a similar manner other construction techniques of making the box can be implemented. As seen in  FIG. 3   a,  the back surface of the box  218  has a circular aperture  301 . This circular aperture  301  can be a little greater than 2 mm in order to accommodate the inner diameter (A) of the evacuation tube (see  FIG. 1   c ). The evacuation tube can be sealed about the periphery of the aperture  301 . In any event, as seen in  FIG. 3   b,  the hole ED has a diameter of approximately 2 mm. There is also shown a getter pill  306  positioned within the getter box. As seen in  FIG. 1   c  the getter box is positioned over the cathode and anode substrates by using the projecting ends  310  and  311  as shown in  FIG. 3   a.  These ends as seen in  FIG. 1   c  are then coupled (via glass frit) to the box as well as the end walls of members  303  and  305 . The getter box has a length designated as LG of about 70 to 90 mm to accommodate the length of the aperture in the peripheral seal of 60 mm and has a width WG of greater than about 4 mm to allow the aperture  301  to be accommodated and to further enable easy securement to the cathode and anode substrates. The use of glass frit seals to secure glass parts together is extremely well known and such techniques are normally implemented by application of appropriate pressure and heat to the glass parts. The sealing of glass parts one to another, either to form the getter box  218  or to provide the seal between the anode and cathode substrates, are well known. 
         [0030]    The getter pill  306  operates to chemically absorb the remaining gas in the envelope of the vacuum container  100  following the evacuation of gases by pumping means. The getter  306  may be installed in a space in the getter box  218  where the getter  306  is fixedly supported therein. As illustrated, the getter pill  306  is provided, on a portion of an inner surface of the getter box  218 . There may be multiple getter pills  306  placed in the getter box  218 . 
         [0031]    Referring to  FIG. 4   a,  there is shown a view of a display with an anode plate  160  secured by means of a glass frit seal  109  to a cathode plate or substrate not shown. As shown in  FIG. 4   a  the getter box  418  now protrudes from the short side and has the evacuation tube  412  secured to a side of the getter box. The getter box  418  shown in  FIG. 4   a  is different in orientation than the getter box shown in  FIG. 1   c.  The getter box  418  is coupled to the anode and cathode substrates by the projecting ends of the getter box. The getter box  418  has the evacuation tube  412  extending from a side surface. The getter box  418  also contains a getter pill  414  and has an aperture  420  which coacts with the aperture  416  in the peripheral seal between the anode and cathode substrates. As indicated above, the length (L) of the aperture  416  is also approximately 60 mm while the width W (not shown) of the aperture is limited by the width of the seal between the anode and cathode which is indicative of the spacing there between. This dimension for W is again 0.2 mm. As seen in  FIG. 4   a,  the getter box which has a length of approximately 70 mm extends over the aperture  416 . The side of the getter box has an aperture  417  which aperture is 2 mm or slightly greater and which aperture accommodates the evacuation tube  412  as seen in  FIG. 4   a.  Also as seen in  FIG. 4   a,  the width of the getter box from the front of the display surface to the back of the getter box is 10 mm. The evacuation tube as indicated has inner diameter of 2 mm where the inner diameter coacts with the aperture  417 . It has an outer diameter of 4 mm, with a wall thickness therefore of 1 mm. The evacuation tube  412  has one wall spaced a distance D of 6 mm from the front wall of the display. The thickness of the wail of the evacuation tube is approximately 1 mm, the inner diameter is 2 mm and therefore the total width of the getter box as shown in  FIG. 4   a  is 10 mm. The length of the getter box which is shown in  FIG. 4   b  as LG is approximately 70-80 mm to cover and enclose the 60 mm aperture. The width of the getter box WG as indicated is 10 mm, with the height of the getter box WH varying as a function of the thickness of the glass substrates comprising the anode and cathode. 
         [0032]    Typically the front surface of the getter box as shown in  FIG. 4   a  can be directly coupled to the front surfaces of the anode and cathode substrates by utilization of a glass frit. Therefore the WH or the height of the getter box can be for example 2.5 mm. If the getter box were 2.5 mm in height, the internal aperture of the getter box would have to interface with the 0.2 mm aperture. If the cathode and anode plates were each 1 mm thick then the surfaces of the getter box in the front would coact with surfaces of the anode and cathode allowing it to be secured thereto by means of a glass frit. Also shown in  FIG. 4   b  is the aperture  416  which basically is shown in  FIG. 4   a  as aperture  417 . The aperture  416  receives the evacuation tube  412 . As seen in  FIG. 4   a  the aperture  416  is dimensioned to accommodate the evacuation tube and is slightly greater than the inner diameter of 2 mm of the evacuation tube. In any event, this difference is insignificant as the evacuation tube operates to efficiently withdraw the air between the cathode and anode substrates and to create an efficient vacuum there between. 
         [0033]    As seen in  FIG. 4   b  the getter box can be fabricated from separate glass plates which are joined together by glass frits. Fabrication of getter boxes or glass boxes from glass members is known in the art. 
         [0034]    It is expressly intended that all combinations of those elements that perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Substitutions of elements from one described embodiment to another are also fully intended and contemplated.