1. A light emitting display device in which a large number of pixels are arranged, said pixel having a structure comprising a data write transistor which charges a light emission maintaining capacitor in accordance with a data signal, a light emission drive transistor which supplies drive current to a light emitting element based on the voltage charged in said light emission maintaining capacitor, and an erase transistor which can discharge the charge voltage charged in said light emission maintaining capacitor, characterized by further comprising a correction voltage write transistor which short circuits a gate and a drain of said light emission drive transistor at a timing at which said erase transistor is turned on and a correction voltage retaining capacitor in which a threshold voltage generated between the gate and a source of said light emission drive transistor is written by a short circuit operation of said correction voltage write transistor, and characterized by being constructed in such a way that said light emission drive transistor supplies the drive current to said light emitting element based on both charge voltages charged in said light emission maintaining capacitor and said correction voltage retaining capacitor.
2. The light emitting display device according to claim 1, wherein a switching transistor is connected in series between said light emission drive transistor and the light emitting element, and said switching transistor is controlled to be in a cut-off state in a state in which said correction voltage write transistor short-circuits the gate and the drain of said light emission drive transistor.
3. The light emitting display device according to claim 2, wherein said erase transistor and the correction voltage write transistor are constituted by TFTs of a same channel, said switching transistor is constituted by a TFT of the channel which is different from that of the former two TFTs, and respective gates of said erase transistor, said correction voltage write transistor, and said switching transistor are commonly connected.
4. The light emitting display device according to any one of claims 1 to 3, wherein said light emitting element is constituted by an organic EL element having at least one or more of light emission functional layers.
5. Electronic equipment into which the light emitting display device according to claim 1 is loaded.
6. A drive method of a light emitting display device in which a large number of pixels are arranged, said pixel having a structure comprising a data write transistor which charges a light emission maintaining capacitor in accordance with a data signal, a light emission drive transistor which supplies drive current to a light emitting element based on the voltage charged in said light emission maintaining capacitor, and an erase transistor which can discharge the charge voltage charged in said light emission maintaining capacitor, characterized by sequentially repeatedly performing
a first step of short-circuiting a gate and a drain of said light emission drive transistor at a timing at which said erase transistor is turned on so as to allow a threshold voltage generated between the gate and a source of said light emission drive transistor to be written in a correction voltage retaining capacitor, and
a second step of supplying light emission drive current to said light emitting element by said light emission drive transistor based on said threshold voltage written in said correction voltage retaining capacitor and a voltage charged in the light emission maintaining capacitor in accordance with said data signal.
7. The drive method of the light emitting display device according to claim 6, wherein at a timing at which said erase transistor is turned on, the gate and the drain of said light emission drive transistor are short-circuited by a correction voltage write transistor so as to allow said threshold voltage to be written in the correction voltage retaining capacitor, and a switching transistor which is connected in series between said light emission drive transistor and the light emitting element is controlled to be in a cut-off state.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A portable pitching mound comprising:
a shell member consisting of a center shell piece, a first shell piece and a second shell piece;
wherein each shell piece has forward and rearward ends, opposite side portions, an upper surface and an opposite underside such that when the shell pieces are placed in a side-by-side relation the shell pieces form an arcuate shell member;
an interlocking means on each shell piece for securing the shell pieces together when the shell pieces are placed in side by side relation; and
at least one of the shell pieces having retractable wheels secured therein such that the shell piece is mobile.
2. The portable pitching mound of claim 1 wherein the interlocking means is a plurality of interlocking sections at the opposite side portions of each shell piece.
3. The portable pitching mound of claim 1 wherein each shell piece has a synthetic surface attached to the upper surface of the shell piece.
4. A portable pitching mound comprising:
a main shell consisting of a center shell piece, a first shell piece and a second shell piece;
the center shell piece having forward and rearward ends, opposite side portions, an upper surface and an opposite underside having at least one retractable wheel disposed therein;
the first side shell piece having forward and rearward ends, opposite side portions, an upper surface and an opposite underside wherein a side portion matingly and detachably receives a side portion of the center shell piece;
the second side shell piece having forward and rearward ends, opposite side portions, an upper surface and an opposite underside wherein a side portion matingly and detachably receives a side portion of the center shell piece such that the pieces form an arcuate shell member; and
wherein during transportation the first and second side shell pieces are detached from the center shell piece and at least one retractable wheel is extended from the center shell piece to provide mobility to the center shell piece.
5. The portable pitching mound of claim 4 wherein the center piece weighs more than the first and second side pieces.
6. The portable pitching mound of claim 4 wherein the center piece has a rubber secured thereto.