the present invention will be described more specifically with reference to the following embodiments . it is to be noted that the following descriptions of preferred embodiments of the present invention are presented herein for purpose of illustration and description only ; it is not intended to be exhaustive or to be limited by the precise form disclosed . fig1 is a schematic view illustrating an electronic musical score display device in operation , the electronic musical score display device comprising an electronic display panel 10 , a manipulator 20 , and a support rack 30 . in order to enable a performer to easily read an electronic musical score , the support rack 30 is provided with a support plate 32 , and the electronic display panel 10 is placed on the support plate 32 under the condition of performance ( operating mode ). it should be noted , when the present invention device is operating ( see fig1 for operating mode ) it is under operating mode , when it is off and put away ( i . e . electronic display panel 10 rolled up ) then it is under storage mode ( see fig3 for storage mode ). the electronic display panel 10 formed with a rectangular electronic paper comprises an cylindrical storage unit 12 , two sides 101 and 102 parallel to the cylindrical storage unit 12 , and fixtures provided at the two sides 101 and 102 ( i . e . the fixtures in fig1 is 14 and 15 ). when the electronic paper is unfolded , the fixtures respectively hook to the right and left sides of support plate 32 and thus the electronic display panel 10 is kept securely unfolded and fixed onto the support plate 32 . practically , in the embodiment , the fixtures are shells 14 and 15 in the shape of a half - tube . inner sides 141 and 151 of the shell 14 and 15 in the shape of a half - tube and is respectively fixed and connected to the sides 101 and 102 of the electronic paper . when the electronic paper is unfolded , the shells 14 and 15 in the shape of half - tube respectively hook to the right and left sides of support plate 32 and thus the electronic display panel 10 is kept securely fixed onto the support plate 32 . in order to display the electronic music score and turn pages , a microprocessor , a memory , a wireless transmission module , and a battery as electronic components are further provided in the cylindrical storage unit 12 . the microprocessor controls the divided pages of musical score data for page turning ( as shown on the electronic display panel 10 ), such that when the microprocessor receives a page turn signal , it will control the divided pages of musical score data for page turn ; the memory is used to store the musical score data ; the wireless transmission module is used to receive the page turn signal and to transmit the musical score data ; the battery act as the power supply to the electronic display panel . a status indicating lamp is further provided in the cylindrical storage unit 12 and emits rays of light from a long transparent area 16 on the surface of cylindrical storage unit 12 , in which the long transparent area 16 cylindrically stretches along the cylindrical storage unit 12 . a power switch 17 is provided at one end of the long transparent area 16 , and a signal receiving / transmission port 18 for the wireless transmission module is formed at the other end . briefly speaking , during performance , the performer may press with the foot on manipulator 20 to turn pages and to read the musical score so that the performance is not interrupted and the page turning function would not be interfered by background noise since there is no voice or sound command involved . it should be especially noted that there are several ways in which the manipulator 20 may be pressed by foot to turn the pages ( i . e . one pressure contact in 3 seconds would generate signal for turning page backward and two rapid pressure contacts in 3 seconds would generate signal for turning page forward ). refer to fig1 and 2 for the details of manipulator 20 . during operation , the manipulator 20 is placed on the floor for the performer to step on it with the foot . practically , in the embodiment , the manipulator 20 is structured with an upper layer 21 and a lower layer 22 . the upper layer 21 is provided with an operation panel mainly for the performer , on which a transparent area 24 and two page turn direction signs 25 and 26 are formed . the main components for controlling the manipulator 20 is provided on the lower layer 22 , comprising a simplified processor , a wireless transmission module , a power supply , and a pressure sensor device or at least one contact switch . these main components ( not shown ) are provided on an upper surface of the lower layer , and placed between the upper layer 21 and the lower layer 22 . the upper layer 21 is connected to the lower layer 22 through a pivot ( provided between the upper layer 21 and the lower layer 22 and not shown ). the contact switches are separately provided at left and right sides of the pivot on the upper surface of lower layer 22 ( can also be think of as between upper layer 21 and lower layer 22 ) and respectively function to generate a signal for turning to a previous page or a signal for turning to a next page when one end of the upper layer 21 receives pressure contact . in other words , there is a contact switch that is located underneath the upper layer 21 , so that as the upper layer 21 shift against the pivot ( like a seesaw with the pivot as the support point ), the end of the upper layer 21 will press one of the contact switches to generate a signal for the microprocessor , and the microprocessor which will control the divided pages of musical score data and turn pages . optionally , a page - turn button or more may be provided on the upper layer 21 and corresponding to a contact switch ( in a 1 to 1 ratio ), wherein the contact switch is provided between upper layer 21 and lower layer 22 , and the page - turn button may be pressed by a foot to shift downwards ( such as a mechanical switch , there would be no shifting downwards for a pressure sensor switch ) and trigger the contact switch to generate a signal for the microprocessor for page turn . further , the contact switch may be replaced with a pressure sensor device . regarding the operational principle , a force is applied by the foot to the pressure sensor device causing the pressure sensing device to connect related circuits in the simplified processor with each other to generate the operation signal , or a force is applied by the foot to press the contact switch ( mechanical ), which connects the related circuits in the simplified processor with each other to generate the operation signal , in both cases the operation signal is transmitted by the wireless transmission module in the manipulator 20 , then received by the wireless transmission module in the cylindrical storage unit 12 , and then the operation signal is processed by the microprocessor to control the page turn . the wireless aspect of the present invention is made possible by the wireless communication module in the cylindrical storage unit 12 and the wireless communication module in the manipulator 20 , and can be bluetooth , ir , or rf . within a preset time , if the pressure sensor device is rapidly pressed several times , different page turn signals may be generated . for example , when the pressure sensor device is pressed one time in three seconds , an operating signal for turning to the next page is generated , and when the sensor device is rapidly pressed two times in three seconds , an operating signal for turning to the previous page is generated . alternatively in another embodiment , a previous page turn button and a next page turn button are provided . when the previous page turn button is pressed with the foot , the related previous page turn control circuit in the simplified processor transmits the previous page turn signal ( wherein , the transmission is done through wireless communication module ); likewise , when the next page turn button is pressed with the foot , the related next page turn control circuit in the simplified processor transmits the next page turn signal . certainly , after the musical scores are arranged , the pages may generally be turned in sequence . thus , only one next page turn button is provided and only the next page turn control circuit is provided in the simplified processor , the object of the present invention is likewise achieved in this single button embodiment . in order to make the electronic musical score display device according to the present invention easily portable , the electronic paper forms the display part of the electronic display panel 10 ( so that the display portion of the electronic display panel 10 can be rolled up ) and the manipulator 20 is made to set on the outer surface of the cylindrical storage unit 12 where the electronic paper is stored , making the whole electronic musical score device smaller and easy to transport and to store . with reference to fig2 , the electronic paper may be rolled as a tape measure and stored in the cylindrical storage unit 12 . after storage , the half - tube shells 14 and 15 are folded in form of a tube and cover the cylindrical storage unit 12 . the half - tube shells 14 and 15 are respectively provided with notches 142 and 152 , and in the condition of storage ( storage mode ), the notches 142 and 152 correspondingly form into a long hollow - out area that exactly exposes the long transparent area ( see fig1 component 16 ) on the surface of cylindrical storage unit 12 , which not only enhances the good look at the time of storage but also allow the user to determine whether the power in the cylindrical storage unit 12 is off at the time of storage for power saving or not . furthermore , the power supply is generally a battery , and a power switch may be added to cut off power to the manipulator when not working in order to achieve power saving and energy conservation . a status indicating lamp may be provided between the upper layer 21 and the lower layer 22 . the status indicating lamp transmits the rays of light out of the transparent area 24 , indicating whether the manipulator 20 is operating or not . in another word , the status indicating lamp indicates the operating status of manipulator 20 . particularly , in the present embodiment , the manipulator 20 has the shape of half - tube , in which a support cushion 23 made of rubber is connected to two cylindrical fringes . when the manipulator 20 is operating , the support cushion 23 ( which is made by rubber ) will contact the ground surface to prevent the manipulator 20 from slipping , by providing additional grip . the manipulator 20 and the support cushion 23 are combined and formed into a tube that may be set around the outer surface of cylindrical storage unit 12 where the electronic display panel is stored . the electronic musical score display device in the condition of storage ( storage mode ) is shown in fig3 . with reference to fig4 as a schematic view illustrating the electronic musical score display device in a second embodiment , the electronic display panel is partially unfolded and partially stored . in the second embodiment , the electronic display panel 60 likewise has an electronic paper on one end that is fixed to the cylindrical storage unit 61 and the other end 62 is connected to an inner wall of the half - tube shell 63 . when the electronic paper ( the display part of the electronic display panel 60 ) is pulled , the half - tube shell 63 is unfolded from the storage unit 61 and thus may also serve as the fixture ( i . e . component 14 of fig1 ) that makes the electronic paper to be securely unfolded . relatively , at the time of storage , the half - tube shell 63 is likewise fixed to the outer surface of cylindrical storage unit 61 ( i . e . component 15 of fig1 ). the long transparent area 64 is also resides in the cylindrical storage unit 61 to serve as a display window for the status indicating lamp provided in the cylindrical storage unit 61 . other crucial parts in the electronic musical score display device in the second embodiment are the same as those in the first embodiment . many changes and modifications in the above - described embodiment of the invention can , of course , be carried out without departing from the scope thereof . for example , the cylindrical storage unit for the electronic paper may have another shape , such as a rectangular rod , a round box , or a square box , and the corresponding manipulator is also designed in a shape corresponding to the shape of the storage unit , and may thus be set around the outer surface of storage unit . while the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments , it is to be understood that the invention needs not be limited to the disclosed embodiment . on the contrary , it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures .