Abstract:
This invention teaches a new generation of prompting system which allows an ordinary user to conveniently couple a LCD based prompting box to a video camera or a camcorder using a universal mounting and adjustment assembly by few steps which are as simple as loosening and fastening few fasteners.

Description:
FIELD OF THE INVENTION 
     This invention generally relates to an autocue displaying device that prompts a person speaking with an electronic visual text of a speech or script. In particular, this invention relates to a prompting system which allows an ordinary user to conveniently couple a LCD based prompting box to a video camera or a camcorder by steps which are as simple as loosening and fastening few fasteners. 
     BACKGROUND OF THE INVENTION 
     Television camera mounted text prompters, commonly known as teleprompters, have been in use nearly since the advent of television. They enable on-camera talent to look directly into the hens of the camera and read a prepared script text that is generated by a computer software program that allows scrolling up of the text so the reader can keep up with the up-corning text as she reads aloud. The reader sees the text reflected from a two-way mirror and the audience can only sees the scene being shot by the camera through the mirror. 
     All such prompters evolved from the days of cathode ray TV tube displays. As a result, they were heavy off-camera devices that had to be mounted below the front of the camera on a “sled” between the camera and the camera pan and tilt head, which is then mounted on a tripod. Typically these prompters were heavy and time-consuming to mount and operate. Usually it takes a minimum of 30 minutes to set-up, align, balance and trim and connect to a personal computer. 
     With the availability of small size, low-cost and lightweight LCD displays; it is now possible to design and build a prompter that is lightweight, mounts in a more industry standard manner and is very quick to mount, set-up and use. 
     It is an object of the present invention to provide a simple, lightweight, compact yet effective prompting system that enables a speaker to look directing into a camera&#39;s lens which is hidden behind a prompting mirror and invisible to the speaker, and at the same time read the textual or other information shown on the prompting mirror, and that can be easily coupled with a video camera or a camcorder which has an accessory adapter shoe on its top. 
     It is a further object of the present invention to provide a prompting apparatus with a shrouded chamber immediately behind an inclined prompting mirror and the camera&#39;s lens is positioned in the chamber a id behind the mirror such that unwanted light is blocked from entering the camera&#39;s lens and the best quality of the recorded images by the camera can be reached. 
     It is a still further object of the present invention to provide a prompting apparatus with a flat display screen facing down to the prompting mirror, which is positioned at a 45 degree angle to the flat display screen, such that unwanted light from the light sources above the apparatus can be blocked from directly shining on the display screen. 
     It is an additional object of the present invention to provide a prompting apparatus with a housing in which the flat display screen is positioned as a ceiling facing down to the prompting mirror, which is positioned at a 45 degree angle to the flat display screen, such that the interference on the display screen and the prompting mirror caused by unwanted light is minimized and the clarity of the images on the prompting mirror viewed by the speaker is maximized. 
     It is yet another object of the present invention to provide a mounting and adjustment assembly which enables a user to couple the prompting apparatus to a video camera or a camcorder which has an accessory adapter shoe on its top. 
     SUMMARY OF THE INVENTION 
     The prompting system according to the present invention includes a LCD based prompter box and a universal mounting assembly to allow adjustment and mounting to most medium sized camcorders or video cameras. 
     The prompter box includes a see through mirror, a housing, and LCD display. The housing has an open front, two opposite shrouding walls, a shrouding bottom, and a rear shrouding wall. The see through mirror, which is approximately 40˜60% reflective and 30˜40% transparent, is securely held in position at a 45 degree angle to the screen surface of the LCD display. The rear shrouding wall has a round opening, or called through-hole, for placing the camera&#39;s lens. 
     The mounting assembly includes a flat mounting bracket, a first shaft, an elongate adjustment bracket, a sub-assembly including a second shaft with a rectangular or square flat base which is for coupling with an accessory adapter shoe on the camera&#39;s top. The flat mounting bracket is secured to the top of the LCD display unit by three or four mounting screws. The first shaft is a threaded mounting shaft being vertically screwed into the flat mounting bracket and tightened down by an internally threaded fastener such as a machine nut or a wing nut. The elongate adjustment bracket has a slot along its length direction. There is an internally threaded hole on one end of the elongate adjustment bracket. The elongate adjustment bracket is screwed onto the first shaft through the hole to the necessary vertical height. When the proper vertical height is realized to allow the center of the through-hole to be aligned with the camcorder&#39;s lens, the adjustment bracket is held in place by one or two internally threaded machine nuts which may be further tightened with a wrench, or by one or two wing nuts which can be tighten by hands. 
     The sub-assembly includes a second shaft with a rectangular or square flat base and fasteners. According to one preferred embodiment of the invention, the second shaft is a dual thread mounting shaft, having an upper portion with a first thread and a lower portion with a second thread. The second shaft is vertical to the rectangular or square flat base. The lower portion&#39;s diameter is larger than the upper portion&#39;s diameter. A first fastener, such as an internally threaded machine nut or a wing nut, is screwed onto the upper portion of the second mounting shaft after the upper portion is inserted into the slot on the elongate adjustment bracket. The first fastener is used to secure the second shaft to the elongate adjustment bracket after the distance between the second shaft and the first shaft is adjusted. After the flat base is inserted into the accessory adapter shoe which is available on all modern camcorders or video cameras, the second shaft can be secured to the camcorder by screwing down a second fastener, such as a machine nut or a wing nut, along the second thread. Preferably, a washer is placed over the second fastener. The washer&#39;s inner diameter is slightly larger than the second shaft&#39;s upper portion&#39;s diameter but less than its lower portion&#39;s diameter such that the washer can be blocked by the lower portion. In operation, the second shaft&#39;s upper portion is inserted into the slot on the elongate adjustment bracket and moved horizontally in the slot until the accessory bracket is aligned with the video camera&#39;s accessory adapter shoe. The first fastener is then fastened to the upper end of the second shaft&#39;s upper portion. Then, the flat base is inserted into the video camera&#39;s accessory adapter shoe on its top. By screwing down the second fastener toward the flat base, the second shaft is secured to the video camera. Accordingly, the prompt box is securely coupled to the video camera. 
     The back of the prompter&#39;s housing has a plastic cover which is held in place by a hook and loop fastener on its&#39; back to provide a light shield for anyone viewing the mirror glass reflecting the prompter information displayed on the screen of the LCD display unit. One side of the prompter box shows a hardware interface, including but not limited to the DC power input required to provide DC power to the LCD display unit, USB input and other electronic connectors. In a typical embodiment, a VGA signal is applied to the LCD display through a connector on the side of the prompter unit. Ventilation holes on the top side of the LCD display unit provide air-flow ventilation to the LCD unit. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram illustrating a perspective view of a typical embodiment of the prompting system according to the present invention which includes a prompting box and a mounting and adjusting assembly coupled thereto; 
         FIG. 2  is a schematic diagram illustrating a front view of the prompting system according to  FIG. 1 ; 
         FIG. 3  is a schematic diagram illustrating a rear view of the prompting system according to  FIG. 1 ; 
         FIG. 4  is a schematic diagram illustrating a left side view of the prompting system according to  FIG. 1 ; 
         FIG. 5  is a schematic diagram illustrating a right side view of the prompting system according to  FIG. 1 ; 
         FIG. 6  is a schematic diagram illustrating a top view of the prompting system according to  FIG. 1 ; 
         FIG. 7  is a schematic diagram illustrating a bottom view of the prompting system according to  FIG. 1 ; 
         FIGS. 8  ( a ),  8 ( b ),  8 ( c ) and  8 ( d ) are schematic diagrams illustrating a top view, a bottom view, a side view and a cross-sectional view, respectively, of a fastener used to secure a dual screw thread mounting shaft to an elongate adjustment bracket according to a typical embodiment of the invention; 
         FIGS. 9  ( a ),  9 ( b ),  9 ( c ) and  9 ( d ) are schematic diagrams illustrating a top view, a bottom view, a side view and a cross-sectional view, respectively, of a fastener used to secure an accessory coupling bracket to a video camera&#39;s accessory adapter shoe according to a typical embodiment of the invention; 
         FIGS. 10  ( a ),  10 ( b ) and  10  ( c ) are schematic diagrams illustrating a bottom view, a top view and a side view, respectively, of a dual screw thread mounting shaft according to a typical embodiment of the invention; and 
         FIG. 11  is a schematic perspective diagram illustrating the dual screw thread mounting shaft according to a typical embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     While the present invention may be embodied in many different shapes, forms, designs or configurations, for the purpose of promoting an understanding of the principles of the invention, reference will be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Any alterations and further implementations of the principle, the essence or the spirit of the invention as described herein are contemplated as would normally occur to one skilled in the art to which the invention relates. 
       FIG. 1  is a diagram illustrating a perspective view of a typical embodiment of the prompting system according to the present invention. The system includes a prompter unit and a mounting and adjusting assembly for coupling the prompter unit to a video camera or a camcorder, herein after referred to as a camera, which has an accessory adapter shoe, usually called accessory shoe, on its top. The prompter unit, also called prompting box, includes an inclined two-way mirror  01 , a case  03 , and a displaying unit  02  which is coupled to the upper side of the case  03 . The displaying unit  02  has an LCD based flat screen which faces down toward the inner space of the case  03  such that the optical image on the flat LCD screen is shown on the two-way mirror  01  and then reflected to the eyes of a speaker who looks into the mirror. 
     The inclined two-way mirror  01  is a see-through mirror with an optical grade of approximately 60˜70% reflective and approximately 30˜40% transparent. The two-way mirror  01  is held in position at a 45 degree angle to the flat LCD screen of the displaying unit  02 . The reflective surface of the mirror faces outward such that the speaker in front of the prompter box can read the textual image reflected from the flat LCD screen. The camera&#39;s lens is placed in the back of the mirror  01  but it is invisible to the speaker. Because the mirror is 30˜40% transparent, the speaker&#39;s image can be caught by the lens and then recorded by the recording device attached to the camera. For the best recording quality, the lens&#39; front surface is approximately at a 45 degree angle to the inclined mirror  01 . 
     The case  03  is also called the housing for the mirror  01  and for the camera&#39;s lens. It can be a molded plastic case, a metal case, an assembled unit of several pieces, or a foldable and collapsible structure for carrying and storing convenience. In a typical configuration, as shown in  FIG. 1  through  FIG. 7 , the case  03  is in a shape of cube or rectangular cuboid and has two opposite side walls paralleling to each other, a bottom side perpendicular to the side malls, an open front and a rear wall  22 . The flat LCD screen  47  of the displaying unit  02  is coupled to the top and constitutes the top side, i.e. the ceiling, of the case  03 . The inclined mirror  01  is in a square or a rectangular shape with a width which is substantially identical to the inner distance between the two opposite side walls. The mirror  01  is fixed to the side walls of the case  03  using the existing art such as by inserting the mirror into two paralleling symmetric grooves embedded in the inner sides of the two opposite side walls. The upper edge of the inclined mirror  01  is affixed to the upper back side of the case  03 , and its lower edge is affixed to the front edge of the bottom side. Preferably, the upper edge of the inclined mirror  01  is fixed to the rear edge of the flat LCD screen  47 . Referring to  FIG. 3 , which is a rear view of the prompter box, the rear wall  22  of the case  03  has a round opening  21 , also called a through-hole, through which the cameras lens is inserted, positioned and aligned. The inclined mirror  01 , the two opposite side walls of the case  03 , the rear wall  22  of the case  03 , and the flat LCD screen  47  of the displaying unit  02  forms an inner chamber where the camera&#39;s lens resides. To block unwanted lights into the chamber, a flexible elastic collar or sleeve can be operatively attached around the round opening  21 . After the lens is inserted into the inner chamber through the opening  21 , the sleeve is internally attached to or locked on the camera, such that unwanted lights cannot enter the chamber from the gap between the round opening  21  and the camera. 
     The case  03  provides a framework to support the flat LCD screen  47 , to hold the inclined mirror  01  in a proper position, to prevent unwanted lights from shedding on the inclined mirror  01 , and to prevent unwanted lights from shedding on the camera&#39;s lens which is placed in the inner chamber and behind the inclined mirror  01 . 
     Referring back to  FIG. 1 , the top or the back of the display unit  02  is mechanically coupled to a mounting and adjusting assembly of hardware. The hardware assembly includes: (1) a flat mounting bracket  04  which is secured to the top side of the display unit  02  by a securing means such as by three or four mounting screws  05  as illustrated in  FIG. 1  and  FIG. 6 ; (2) a threaded shaft  06  which is vertically coupled to the flat mounting bracket  04  by a securing means such as by screwing the shaft  06  into the flat mounting bracket  04  and being tightened down by a fastener such as a machine nut  08 , which can be a wing nut; (3) an elongate adjustment bracket  09  which is screwed onto the threaded shaft  06  to a necessary vertical height and held in place by two fasteners such as machine nuts  07  and  07   a , which can be wing nuts; (4) a sub-assembly including a dual screw thread mounting bracket  10  which is slidably coupled to the elongate adjustment bracket  09  through a slot  14 , a washer  12  which is placed over a first thread  41  on the upper portion of the mounting bracket  10 , an internally threaded fastener  13  for securing the bracket  10  on the adjustment bracket  09 , a flat rectangular or square base  44 , and another internally threaded fastener  11  coupled to a second thread  42  on the lower portion of the mounting bracket  10  for securing the flat base  44  to a camera&#39;s accessory adapter shoe. 
     The internal thread of the fastener  13  matches with the first thread  41 . The internal thread of the fastener  11  matches with the second thread  42 . In the typical embodiment, the external diameter of the second thread  42  is larger than the external diameter of the first thread  41 . The internal diameter of the washer  12  is slightly larger than the external diameter of the first thread  41  such that the washer can be easily slide over the first thread  41 , and is smaller than the external diameter of the second thread  42  such that the lower portion of the bracket  10  blocks the washer  12 . When the fastener  11  is screwed down against the flat base  44 , it secures the flat base  44  to the camera&#39;s accessory adapter shoe. When the fastener  13  is screwed down against the washer  12 , it secures the mounting bracket  10  to the adjustment bracket  09 . To strengthen the coupling with the flat base  44 , the fastener  11  may have an internal cup structure with a diameter d 4  as shown in  FIGS. 9(   b ),  9 ( c ) and  9 ( d ). Further, the fastener  13  may have a convex member on one side for a better coupling, as shown in  FIG. 4 ,  FIG. 5  and  FIG. 8 . Similarly, the fastener  11  may have a convex member  38  on one side, as shown in  FIG. 1 ,  FIG. 4 ,  FIG. 5  and  FIG. 9 . 
     Referring to  FIG. 11 , which is a schematic perspective view of the dual screw thread mounting bracket  10  for the sub-assembly discussed above. The dual screw thread mounting bracket  10  includes a flat base  44  at its bottom and a threaded shaft vertical to the flat base  44 . The flat base  44  is preferably in a rectangular shape for convenient coupling with the camera&#39;s accessory adapter shoe. The shaft includes a first thread  41  in its upper portion, a second thread  42  in its lower portion and a non-threaded end  43  between the second thread  42  and the flat base  44 .  FIG. 10(   a ),  FIG. 10(   b ) and  FIG. 10(   c ) illustrate a bottom view, a top view and a side view of the mounting bracket  10  respectively. In a typical embodiment of the invention, the first thread  41  is a ¼-20 thread and the second thread  42  is a ⅜″-16 thread. The width and thickness of the flat base  44  are ¾″ and ⅛″ respectively. 
     In operation, the internally threaded fastener  11 , which is a machine rut or a wing nut, is screwed onto the second thread  42  of the mounting bracket  10 .  FIG. 9(   a ),  FIG. 9(   b ),  FIG. 9(   c ) and  FIG. 9(   d ) illustrate a top view, a bottom view, a side view, and cross-sectional view of the fastener  11  respectively. The flat base  44  is inserted into the accessory adapter shoe on the top of the camera. By screwing down the fastener  11 , the mounting bracket  10  is secured to the camera. By sliding the mounting bracket  10  along the slot  14  on the adjustment bracket  09 , the camera&#39;s lens is horizontally adjusted for a most appropriate position. After the lens&#39; horizontal position is determined, the mounting bracket  10  can be secured to the adjustment bracket  09  by screwing down the internally threaded fastener  13 , which can be a machine nut or a wing nut.  FIG. 8(   a ),  FIG. 8(   b ), FIG.  8 ( c ) and  FIG. 8(   d ) illustrate, respectively, a top view, a bottom view, a side view, and cross-sectional view of a machine nut  13  used as a fastener. 
     Referring to  FIG. 1 ,  FIG. 4 ,  FIG. 5  and  FIG. 11 , the elongate adjustment bracket  09  can range in thickness from ⅛″ to ⅜″, depending on the materials used. The slot  14  is an elongate open space which allows the mounting bracket  10  to slide horizontally. The external diameter of the first thread  41  of the mounting bracket  10  is slightly smaller than the width, i.e., the narrower measurement, of the slot  14  such that the mounting bracket  10  can be moved horizontally in the slot  14  until the flat base  44  is properly aligned with the camera&#39;s accessory adapter shoe and held in position by the internally threaded fastener  11 . 
     For the designed operational purpose, the elongate adjustment bracket  09  is paralleled to the flat mounting bracket  04 , and is perpendicular to the mounting shaft  06  and the mounting bracket  10 . 
       FIG. 3  illustrates the rear view of the prompting system. The rear wall or back cover  22  of the prompter unit can be a detachable plastic board according to one typical implementation of this invention. The back cover  22  can be held in place by a hook and loop fastener (not shown). In another implementation, the back cover  22  can be affixed to the two opposite side walls and the bottom side permanently. To block unwanted lights from entering the inner chamber described above, a flexible or elastic sleeve or lining (not shown) is affixed around the edge of the opening  21 . 
     To avoid unwanted light reflection, the inner sides of the prompter&#39;s case, i.e. inner sides of the opposite walls, the inner side of the bottom and the inner side of the rear wall or back cover are coated or lined with an anti-reflection layer. 
     The hardware mounting and adjustment assembly described above can be further modified in several aspects without changing the spirit and scope of this invention. First, the flat mounting bracket can be embedded in or integrated with the backbone of the display unit such that a user just needs to screw a first threaded shaft, i.e. the mounting shaft  06 , into an internally threaded hole on the back of the display unit and secure it by a first fastener. Second, the elongate adjustment bracket  09  is screwed onto the mounting shaft  06  and then secured by a single fastener, called the second fastener. Three, the sub-assembly of the mounting bracket  10  includes a second threaded shaft, a flat rectangular or square base and three fasteners—after the second threaded shaft is inserted into the slot  14 , it is secured by a third fastener above the slot  14  and a fourth fastener below the slot  14 , and a fifth fastener is used for securing the second threaded shaft to the camera&#39;s accessory adapter shoe. Four, to further reduce the manufacturing cost, the first threaded shaft and the second threaded shaft have the same helical properties and the five fasteners mentioned in this paragraph can be identical. Optionally, five identical washers can be used with the five identical fasteners. 
     Referring back to  FIG. 1  and  FIG. 5 , the electrical interface such as the DC power input  45  and a signal input  46  can be configured in a panel  30  on one side of the displaying unit  02 . The signal generated from a PDA, a tablet, a laptop or a desktop PC is applied to the LCD displaying unit through the signal input  46 . The inverted textual image is shown on the flat LCD screen. Upon reflection, the speaker in front of the prompter can read the textual image in its normal format. On the top of the displaying unit  02 , the ventilation holes  31  and  32  as shown in  FIG. 6  provide air-flow ventilation to the LCD display unit. 
     In another preferred embodiment of the invention, the displaying unit  02  can be a lightweight computing device with an incorporated processor and an LCD based display screen, forming a compact self-contained unit, such as but not limited to a notebook, a tablet, an iPad or iPod, a smart mobile phone. The unit runs a prompting software application and the pre-designed prompting text or other information is displayed on the display screen at a speed that the speaker feels comfortable to read. The unit may have a wireless remote control function which enables the speaker to adjust the moving speed of the script or images on the mirror. 
     Yet, in another preferred embodiment of the invention, the displaying unit  02  can be a mobile phone or other type of electronic device which has an LCD display. The prompter&#39;s housing includes a frame and a coupling means, such an insert-and-lock means, which enables a user to insert or slide in a tablet device to fulfill the functions of the display unit described above. The tablet device runs a prompting software application and the pre-designed text or other message is displayed on the LCD screen at a speed that the speaker feels comfortable to read. 
     While one or more embodiments of the present invention have been illustrated above, the skilled artisan will appreciate that modifications and adoptions to those embodiments may be made without departing from the scope and spirit of the present invention.