Abstract:
A keyboard with elevated keys for a notebook computer. The keys of the keyboard are elevated when the notebook computer is opened, and can be depressed when the flat display is closed. The keyboard has keys movably connected to the foundation sheet through scissors-type linking mechanisms. A plurality of guiding sheets is movably disposed on a foundation sheet and has hooks and tracks. Each of the tracks is parallel to a first direction. A sliding member is movably disposed on the foundation sheet and has protrusions extending into each of the tracks. When the sliding member moves in the first direction, the protrusions move the guiding sheets from a first position to a second position. The hooks of the guiding sheets sequentially press the scissors-type linking mechanism of each key to depress the keys of the keyboard from elevated position to depressed position.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a keyboard with elevated keys, and in particular to a keyboard with keys that can be elevated sequentially. 
     2. Description of the Related Art 
       FIG. 1A  is an exploded view of an elevated key of a conventional keyboard. In order to simplify the drawing,  FIG. 1  only shows one elevated key of a conventional keyboard. In  FIG. 1A , the elevated key of a keyboard for a notebook computer includes a key cap  11 , a cap support  12 , an elastic sheet  13 , a circuit membrane assembly  14 , a base sheet  15  and a guiding sheet  16 . 
     The base sheet  15  is a metal sheet on which two seats  151  and a hook  152  are formed by punching and contacting. 
     The circuit membrane assembly  14  is disposed on the base sheet  15 . It comprises the circuit of the keyboard and a plurality of holes  141  with respect to the seats  151  and the hook  152  of the base sheet  15 . 
     The elastic sheet  13  has a sheet-like body, an elastic dome  131 , a connecting portion  133  and holes  132 . The connecting portions  133  connect the elastic dome  131  and the sheet-like body. Further, the elastic dome  131  has a plunger (not shown) inside to contact the circuit membrane assembly  14  and conduct the circuit on thereto. 
     The guiding sheet  16  is disposed on the elastic sheet  13  and can be moved horizontally. It has two L-shaped hooks  161  and a hole  163  with respect to the elastic dome  131  of the elastic sheet  13  and the seats  151  and the hook  152  on the base sheet  15 . 
     The cap support  12  has a first linking bracket  121  and a second linking bracket  122  which hinged together and as a scissors-type support mechanism. Furthermore, the first linking bracket  121  has shaft rods  1212 ,  1213  formed on both sides thereon. The second linking bracket  122  has shaft rods  1221  formed on both sides thereon. 
       FIG. 1B  is a schematic back view of a key cap of the elevated key in  FIG. 1A . In  FIG. 1B , the key cap  11  has hooks  111  and holding portions  112  on its bottom surface. 
       FIG. 1C  is a schematic view of the elevated key in  FIG. 1A  with the key cap removed. In  FIGS. 1A˜1C , while assembling the conventional elevated key, the circuit membrane assembly  14 , the elastic sheet  13  and the guiding sheet  16  are put on the base sheet  15 . The seats  151  and the hook  152  of the base sheet  15  protrude through the holes  141  of the circuit membrane assembly  14 , the holes  132  of the elastic sheet  13  and the hole  163  of the guiding sheet  16 . The key cap  11  is mounted on the base sheet  15  via the cap support  12 . The shaft rods  1212  are inserted into the seats  151  so that the first linking bracket  121  is rotatable with respect to the base sheet  15 . The narrow portion  1223  of the second linking bracket  122  is hooked by the hook  152  of the base sheet  15  so that the second linking bracket  122  is also rotatable with respect to the base sheet  15 . The hooks  111  hold the shaft rods  1213  of the first linking bracket  121 , and the holding portions  112 , hold the shaft rod  1222  of the second linking bracket  122 . Furthermore, in  FIG. 1C , the L-shaped hooks  161  selectively press both arms of the first linking bracket  121 . 
     In operation, the user pushes down the key cap  11  and compresses the elastic dome  131 . Then, the elastic dome  131  deformed and pushes the circuit membrane assembly  14  so that an electric conduction therein is induced and sends out a corresponding signal. 
       FIG. 2A  and  FIG. 2B  are cross sections of the elevated key according to the  FIG. 1A  when the guiding sheet is in a first position and in a second position correspondingly. In  FIG. 2A , when the guiding sheet  16  is in the first position, the hooks  161  contact both arms of the first linking bracket  121 , and the key cap  11  is in the original typing position. In  FIG. 2B , when the guiding sheet  16  is in the second position, the hooks  161  presses both arms of the first linking bracket  121 . The scissors-type support structure approaches the base sheet  15 , such that the key cap  11  descends to the depressed position. Furthermore, when the guiding sheet  16  returns to the original position in  FIG. 2A  from the depressed position, the hooks  161  release the first linking bracket  121 , or the scissors-type linking mechanism. The elastic dome (not shown) provides an elastic force to elevate the key cap  11 . 
     The conventional keyboard for a notebook computer has at least 100 keys. The friction force between the guiding sheet  16  and the arms of the first linking bracket  121  is very large when moving the guiding sheet  16  to depress all of the keys  11 . Thus, it needs a thick guiding sheet to provide a large horizontal force to overcome the friction and contact all of the keys at the same time, but the thick guiding sheet increases the profile weight of the notebook computer. 
     SUMMARY OF THE INVENTION 
     Accordingly, an object of the invention is to provide a keyboard with sequentially elevated keys. The keys of the keyboard are divided into several groups, which can be elevated sequentially by a plurality of guiding sheets, to reduce the required horizontal force and the thickness and rigidity of the guiding sheets. 
     Another object of the invention is to provide a keyboard with elevated keys for a notebook computer. The keys of the keyboard can be selectively elevated or depressed by a plurality of horizontally moved guiding sheets, to be elevated when the flat display of notebook computer is open and can be depressed when the flat display is closed. Thus, the notebook computer has a thinner profile. 
     The present invention provides a keyboard with elevated keys. The keyboard has a foundation sheet, a plurality of key sets, a plurality of guiding sheet, a sliding member and a connecting belt. The keys are movably connected to a foundation sheet through scissors-type linking mechanism between elevated position and depressed position. The guiding sheets have hooks and tracks which parallel to a first direction, respectively. The guiding sheets are disposed on a foundation sheet and can be moved in a second direction. The distance between each of two neighboring guiding sheets is a first interval. The sliding member is movably disposed on the foundation sheet and has protrusions extending into each of the tracks. The distance between each of two neighboring protrusions is a second interval. The first intervals between each of the two neighboring guiding sheets are unequal to the second intervals between two neighboring protrusions. When the sliding member moves in the first direction, the protrusions move the guiding sheets from the first position to the second position. The hooks of the guiding sheets push the scissors-type linking mechanism to depress the keys. 
     According to the invention, the first direction is perpendicular to the second direction. Each of the scissors-type linking mechanism includes a first linking bracket and a second bracket pivoted together. Each of the keys has an elastic dome disposed under the key cap. 
     Moreover, when the sliding member moves in the second direction, the protrusions move the guiding sheets from the is second position to the first position, such that the hooks release the scissors-type linking mechanisms, and the key caps are elevated by the elastic domes. 
     Each of the tracks has a first portion, a second portion, and a connecting portion. The first portion and the second portion are parallel to the first direction and connected by the connecting portion. The distance between the first portion and the second portion is a third interval, equal to the distance between the first position and the second position. 
     The present invention also provides a keyboard for a notebook computer. The keyboard is assembled in the main body of the notebook computer. The keyboard has a plurality of keys movably connected to a foundation sheet through scissors-type linking mechanism between elevated position and depressed position. A plurality of guiding sheets are movably disposed on a foundation sheet and have hooks and tracks. Each of the tracks is parallel to a first direction. A sliding member is movably disposed on the foundation sheet and has protrusions extending into each of the tracks. The first intervals between two neighboring guiding sheets are unequal to the second intervals between two neighboring protrusions. When the flat display of the notebook computer is closed, the sliding member is pushed along the first direction and the protrusions move the guiding sheets from the first position to the second position. The hooks of the guiding sheets contact the scissors-type linking mechanism to depress the keys. 
     Moreover, the first direction is perpendicular to the second direction. Each scissors-type linking mechanism includes a first linking bracket and a second bracket pivoted together. Each of the keys has an elastic dome disposed under the key cap. 
     Moreover, an operating means for providing an elastic force to the sliding member is applied. When the flat display is open, the sliding member moves in the second direction, and the protrusions move the guiding sheets from the second position to the first position, such that the hooks release the scissors-type linking mechanisms, and the elastic domes elevate the key caps. 
     Each of the tracks has a first portion, a second portion and a connecting portion. The first portion and the second portion are parallel to the first direction and connected by the connecting portion. the distance between the first portion and the second portion is a third interval, equal to the distance between the first position and the second position. 
     A detailed description is given in the following embodiments with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein: 
         FIG. 1A  is an exploded view of elevated keys of the conventional keyboard as referenced in the Prior Art; 
         FIG. 1B  is a schematic back view of a key cap of the elevated key in  FIG. 1A ; 
         FIG. 1C  is a schematic view of the elevated key removing the key cap in  FIG. 1A ; 
         FIG. 2A  is a cross section of the elevated key when the guiding sheet is in a first position; 
         FIG. 2B  is a cross section of the elevated key when the guiding sheet is in a second position; 
         FIG. 3  is an exploded view of a 3×3 keyboard with elevated keys of the invention; 
         FIG. 4A  is a schematic top view of the keyboard when the sliding member is at the original place; 
         FIG. 4B  is a schematic side view of the keyboard when the sliding member is at the original place; 
         FIG. 4C  is another schematic top view of the keyboard when the sliding member is at the midpoint; 
         FIG. 4D  is another schematic side view of the keyboard when the sliding member is at the midpoint; 
         FIG. 4E  is another schematic top view of the keyboard when the sliding member is at the end; 
         FIG. 4F  is another schematic side view of the keyboard when the sliding member is at the end; 
         FIG. 5A  is a schematic view of a notebook computer having the keyboard with elevated keys of the invention; and 
         FIG. 5B  is an enlarged section view of the operating assembly of the keyboard in  FIG. 5A . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 3  is an exploded view of a keyboard with elevated keys of the invention. In order to simplify the drawing,  FIG. 3  only shows a 3×3 array of the keyboard and an elevated key structure of the invention. In  FIG. 3 , the keyboard of the invention comprises a foundation sheet, a sliding member  30 , a plurality of guiding sheets  20   a ˜ 20   c  and a plurality of key sets (only one key is shown in  FIG. 3 ). 
     The foundation sheet includes a base sheet  15 , a circuit membrane assembly  14  and an elastic sheet  13 . The structure and assembly method are described in the Prior Art. Furthermore, the cap support  12  includes a first linking bracket  121  and a second linking bracket  122 . The first linking bracket  121  of the cap support  12  can be pressed or released by the hooks  21  of the guiding sheet  20   a  to depress or elevate the key cap  11 . 
     In this embodiment, a whole guiding sheet in the Prior Art is divided into a plurality of guiding sheets  20   a ˜ 20   c . They are long narrow metal strips parallelly disposed on the foundation sheet to reduce both the friction force when moving. horizontally, and the thickness of the keyboard. Referring to the  FIG. 3 , the distances between the centerlines of the guiding sheets  20   a ˜ 20   c  are equal to a first interval d. Using the guiding sheet  20   a  as an example, the guiding sheet  20   a  has three pairs of L-shaped hooks  21 , three holes  23  and a Z-shaped track  24   a . The holes  23  allow the elastic domes  131  on the elastic sheet  13  and the seats  151  and hooks  152  of the base sheet  15  to pass through. The hooks  21  are formed by punching and contacting. Each of the hooks  21  has a horizontal portion  211  and a vertical portion  212  and forms an inverted L-shaped hook. The hooks  21  contact the first linking bracket  121  to depress the key cap  11 . That is the horizontal portions  211  of the hooks  21  start pressing the arms of the first linking bracket  121  when the guiding sheet  20   a  starts moving from a first position to a second position. The hooks  21  do not contact the cap support  12  when the guiding sheet  20   a  is in a first position, and the hooks  21  depress the cap support  12  to a depressed position when the guiding sheet  20   a  is in a second position. The total thickness of the keyboard is reduced because the key cap  11  is received in a depressed position. 
     The Z-shaped track  24   a  has a first portion  241   a , a second portion  242   a  and a connecting portion  243   a . The diagonal connecting portion  243   a  connects the first portion  241   a  and the second portion  242   a . The first portion  241   a  and the second portion  242   a  are parallel to each other in a first direction and perpendicular to the longitudinal centerline, or a second direction, of the guiding sheet  20   a . The distance between the first portion  241   a  and the second portion  242   a  of the Z-shaped track  24   a  is defined as a third interval p. It is equal to the distance between the first position and the second position of the guiding sheets  20   a.    
     The sliding member  30  is a thin metal or plastic board disposed on the foundation sheet. The sliding member  30  has three protrusions  31   a ˜ 31   c . The distance between neighboring protrusions is defined as a second interval D, smaller than the first interval d. The sliding member  30  can move in the direction perpendicular to the longitudinal centerline of the guiding sheets  20   a ˜ 20   c . The protrusions  31   a ˜ 31   c  extend into the tracks  24   a ˜ 24   c  of the guiding sheets  20   a ˜ 20   c . When the sliding member  30  moves in the first direction, the protrusions  31   a ˜ 31   c  sequentially move the guiding sheets  20   a ˜ 20   c  by a distance of the third interval p. Thus, the hooks  21  of the guiding sheets  20   a ˜ 20   c  can depress or release the cap supports  12  to depress or elevate the keys relating to the foundation sheet. 
     The details of storing the keys of the keyboard of the invention are provided as follows. In order to simplify the drawings,  FIGS. 4B ,  4 D and  4 F do not show the elastic domes. 
       FIGS. 4A and 4B  are schematic top and side views of the keyboard when the sliding member is in the original position. In  FIGS. 4A and 4B , the second interval D is smaller than the first interval d. When the protrusion  31   c  is at the end of the first portion  241   c  of the track  24   c , the protrusion  31   b  is at the intermediate zone of the first portion  241   b  of the track  24   b , and the protrusion  31   a  is at the intersection of the first portion  241   a  and the connecting portion  243   a  of the track  24   a . In the meantime, the cap supports  12  of the keys are not depressed and in the elevated position. 
       FIGS. 4C and 4D  are schematic top and side views of the keyboard during the sliding member is moved. In  FIGS. 4C and 4D , because the second interval D between each neighboring protrusions  31   a ˜ 31   c  is smaller than the first interval d between each neighboring guiding sheets  20   a ˜ 20   c , the protrusion  31   a  pushes the guiding sheet  20   a  leftward at a third interval p while the sliding member moving downward, and the protrusion  31   a  moving into the intersection of the second portion  242   a  and the connecting portion  243   a  of the track  24   a . The cap supports  12   a  disposed over the guiding sheet  20   a  are depressed, and the key caps  11   a  are in the depressed position. Furthermore, the protrusion  31   b  moves into the intermediate zone of the connecting portion  243   b  of the track  24   b , and the protrusion  31   c  moves into the intersection of the first portion  241   c  and the connecting portion  243   c  of the track  24   c  because the second interval D is smaller than the first interval d. The protrusion  31   b  starts pushing the guiding sheet  20   b  leftward, the cap supports  12  disposed over the guiding sheet  20   b  are depressed slightly, and the key caps  11   b  are at the midpoint between the elevated position and the depressed position. The key caps  11   c , however, are in the original position because the guiding sheet  20   c  is not moved. 
       FIGS. 4E and 4F  are schematic top and side views of the keyboard when the sliding member is at the end. In  FIGS. 4E and 4F , the second interval D is smaller than the first interval d. While the sliding member keeps moving downward, the protrusions  31   b ,  31   c  push the guiding sheets  20   b ,  20   c  leftward at a first interval p. The cap supports  12  disposed over the guiding sheets  20   b ,  20   c  are depressed by the hooks  21   b ,  21   c . All of the key caps  11   a ˜ 11   c  are depressed to the depressed position. 
     While the sliding member  30  moves upward to the first position from the second position, the guiding sheets  20   a ˜ 20   c  are sequentially guided rightward, and the key caps  11   a ˜ 11   c  are released sequentially. In  FIGS. 4E and 4F , the key caps are in the depressed position, initially. While the sliding member  30  keeps moving upward and, the guiding sheet  20   c  moves rightward, shown in  FIGS. 4C and 4D , the hooks  21   c  of the guiding sheet  20   c  release the cap supports  12   c  of the guiding sheet  20   c . The key caps  11   c  are elevated by the elastic force of the elastic domes and return to the elevated position. In  FIGS. 4A and 4B , the key caps  11   a  and  11   b  are elevated sequentially. 
     Moreover, the guiding sheets  20   a ˜ 20   c  are not limited to disposal the elastic sheet  13 . They can be disposed between the elastic sheet  13  and the circuit membrane assembly  14 , or between the circuit membrane assembly  14  and the base sheet  15 . The first interval d between the guiding sheets also can be smaller the second interval D, such that the order in which the key caps are pressed or elevated is reversed. 
     The keyboard with elevated keys of the invention can be used in a notebook computer.  FIG. 5A  is a schematic view of the notebook computer having the keyboard with elevated keys of the invention.  FIG. 5B  is an enlarged section view of the operating assembly of the keyboard in  FIG. 5A . In  FIGS. 5A and 5B , a notebook computer  500  has a flat display  510  pivoted on a main body  520  via two hinges  521 . The keyboard  530  of the invention is assembled in the main body  520  of the notebook computer  500 . The keyboard  530  has a plurality of guiding sheets  531  with tracks  5311  arranged at both ends. The main body  520  of the notebook computer  500  further includes two sliding members  540  disposed beside the keyboard  530 . The sliding members  540  have a plurality of protrusions  541  by which the guiding sheets  531  can be pushed rightward or leftward, such that the keys of the keyboard  530  can be depressed in a depressed position or elevated to an elevated position. Furthermore, the operating assembly includes connecting belts  522  and springs  523 . The connecting belt  522  connects one end portion of a sliding member  540  to the hinge  521  of the flat display  510 . The spring  523  connects the other end portion of the sliding member  540  and a seat  524  of the main body  520 . 
     Referring to  FIGS. 5A and 5B , the sliding members  540  move to the flat display  510  when the flat display  510  is closed. The guiding sheets  531  move leftward and the keys of the keyboard are depressed to the depressed position. The sliding members  540  move opposite to the flat display  510  by the elastic force of the springs  523  when the flat display  510  is open. The guiding sheets  531  move rightward and the keys of the keyboard are released to the normal position. 
     According to the embodiments provided above, the keyboard with sequentially elevated keys of the invention can reduce required horizontal force as well as thickness and rigidity of the guiding sheets. 
     Moreover, the keys of the keyboard can be elevated by a plurality of horizontally moving guiding sheets. The keys of keyboard can be elevated when the flat display of notebook computer is open and can be depressed when the flat display closes. Thus, the thickness and weight of the notebook computer with elevated keys can be reduced, and the notebook computer with this keyboard of the invention has a thinner profile. 
     While the invention has been described by way of example and in terms of the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.