JP2000250475A5 - - Google Patents

Description

Patent application title: Column wiring drive circuit and image display device

[0021]
[Means for Solving the Problems]
The present invention is used in an image display apparatus having a matrix image display panel having column wirings and row wirings and electron-emitting devices connected to the column wirings and row wirings, and of a modulation signal modulated by a pulse width modulation circuit. A column wiring drive circuit that receives an output and outputs a column wiring drive signal for driving an electron emission element connected to the column wiring, the complementary switching circuit, and between the complementary switching circuit and the column wiring. resistors and have, in a first period corresponding to the change of the output of said modulation signal and outputs a column wire drive signal at the output impedance which is determined by the resistor and the complementary switching circuit, said first From the complementary switching circuit receiving the output of the modulation signal to the column wiring after the period of The circuit may further include a circuit that controls the column wiring drive signal to be output to the column wiring with an impedance lower than the first period .

[0022]
Further, according to the present invention, there is provided a matrix image display panel having column wiring and row wiring and electron emitting elements connected to the column wiring and row wiring, and an output of a modulation signal modulated by a pulse width modulation circuit. And a column wiring drive circuit for outputting a column wiring drive signal for driving an electron emission element connected to the column wiring, the column wiring drive circuit comprising a complementary switching circuit, and the complementary switching. A resistor between the circuit and the column wiring, and outputting a column wiring drive signal with an output impedance determined by the complementary switching circuit and the resistor in a first period corresponding to a change in the output of the modulation signal From the complementary switching circuit receiving the output of the modulation signal after the first period. Serial, characterized by further comprising a circuit for controlling to output the column wire drive signal to the column lines at a lower impedance than the first period for the column wirings.

[0024]
[ Reference Embodiment]
Hereinafter, a reference embodiment will be described. A matrix image display panel used in an image display apparatus according to the present invention basically comprises a multi-electron source in which a large number of electron sources such as cold cathode electron emitters are arrayed on a substrate in a thin vacuum vessel; It is provided opposite to an image forming member for forming an image by electron irradiation.

[0070]
Second Embodiment
Next, a second embodiment according to the present invention will be described. The second embodiment is an embodiment in which the column wiring drive circuit P1104 is different from the reference embodiment. Since the other configuration is the same, the description of the configuration other than the column wiring drive circuit P1104 will be omitted.

[0072]
In FIG. 5, since the PWM generator unit P1102 operates in the same manner as the reference embodiment, the description will be omitted. The PWM generator unit P1102 outputs a high level with a pulse width proportional to the size of the luminance data (image information) as in the reference embodiment.

[0073]
In the column wiring drive circuit P1104, P1104a is a complementary switching circuit as in the reference embodiment, and P1104b is a resistor whose resistance value is determined so that ringing does not occur by the display panel P2000 as in the reference embodiment. . P1104f is a switch circuit which turns on / off input / output by control input. P1106 is an enable control circuit, which comprises, for example, a latch circuit P1106a as an enable generator as shown in FIG. 6 and an exclusive OR circuit P1106b, and as shown by T110a in the timing chart shown in FIG. Only the rising and falling of the output T110 of P1102 become LOW level.

[0075]
As shown in FIG. 5, the details of the complementary switching circuit P1104a are the same as in the reference embodiment, as shown in FIG.

[0076]
Further, similarly to the reference embodiment, a pulse width high level signal proportional to the size of the luminance data (image information) output from the PWM generator unit P1102 is output. Then, the logic level of the high level signal is inverted by the NOT circuit P1104c, the signal is inverted again by the P-type MOSFET P1104d and the N-type MOSFET P1104e which are output circuits, and the power supply voltage is output.

[0080]
(1) Since the output of the enable control circuit P1106 is at low level at the time of rising and falling, the resistor P1104b enters in series between the complementary switching circuit P1104a and the column wiring as in the reference embodiment, so no ringing occurs. Can drive the column wiring.

[0081]
(2) Furthermore, since the output of the enable control circuit P1106 is at high level during times other than rising and falling, the resistor P1104b is short-circuited by the switch circuit P1104f, so that voltage drop and power loss are small.
And the like, and the image display panel P2000 can be driven well without power loss, as compared to the reference embodiment which has the advantages of the above.

[0082]
Further, the value of the resistor P1104b is determined so that ringing does not occur as in the reference embodiment.

[0087]
In FIG. 8, the PWM generator unit P 1102 operates in the same manner as in the reference embodiment, and thus the description thereof is omitted. The PWM generator unit P1102 outputs the time high level of the pulse width proportional to the size of the luminance data (image information) as in the reference embodiment.

[0088]
In the column wiring drive circuit P1104, P1104a is a complementary switching circuit as in the reference embodiment, and P1104b is a resistor whose resistance value is determined by the matrix display panel as in the reference embodiment. P1104g is a three-state complementary switching circuit, which can put the output into a high impedance state by the control input.

[0097]
(2) Since the output of the enable control circuit P1106 is at high level during times other than rise and fall (the enable input of the three-state complementary switching circuit P1104g is at high level, the output of the three-state complementary switching circuit P1104g is Since the column wiring is driven by the output impedance in which the complementary switching circuit P1104a and the three-state complementary switching circuit P1104g are connected in parallel, the voltage drop and the power loss are small.
And the like, and could drive the image display panel P2000 even better than the reference embodiment which was good.

[0098]
In the same manner as in the reference embodiment, the value of 100 [Ω] to 1 [kΩ] is optimum for a panel of about 10 ′ ′, and the value of the resistor P1104 b is 500 Ω or more for a large panel of 30 ′ ′ or more. 5 [kΩ] was optimal.

[0102]
In FIG. 10, the PWM generator unit P1102 operates in the same manner as the reference embodiment, so the description will be omitted. The PWM generator unit P1102 outputs the time high level of the pulse width proportional to the size of the luminance data (image information) as in the reference embodiment.

[0104]
Also, P1104b is a resistor whose resistance value is determined by the matrix display panel as in the reference embodiment.

[0112]
(2) Other than rising and falling, the enable control circuit P1106 outputs the low level enable signal to the three-state complementary switching circuit P1104g1 and the high level enable signal to the three-state complementary switching circuit P1104g2. As a result, the three-state complementary switching circuit P1104g1 becomes a high impedance output and does not affect the column wiring drive. On the other hand, the three-state complementary switching circuit P1104g2 outputs the output of the PWM generator unit P1102 as it is. From this output, since the three-state complementary switching circuit P1104g2 drives the column wiring with low impedance, voltage drop and power loss are small.
And the like, and could drive the image display panel P2000 even better than the reference embodiment which was good.

[0113]
As in the reference embodiment, the value of 100 [Ω] to 1 [kΩ] is optimum for the display panel of about 10 ′ ′, and the value of the resistor P1104 b is 500 [Ω] for a large panel of 30 ′ ′ or more. ~ 5 [kΩ] was optimal.

[0116]
In FIG. 13, the PWM generator unit P 1102 operates in the same manner as the reference embodiment, so the description will be omitted. The PWM generator unit P1102 outputs the time high level of the pulse width proportional to the size of the luminance data (image information) as in the reference embodiment.

[0117]
In the column wiring drive circuit P1104, P1104a is a complementary switching circuit as in the reference embodiment, and P1104b1 is a first resistor whose resistance value is determined by the matrix display panel as in the reference embodiment. P1104g1 is a three-state complementary switching circuit, which enables the output to be in a high impedance state by the enable input. P1104b2 is a second resistor whose resistance value is determined by the matrix display panel as in the reference embodiment.

[0127]
In the same manner as the reference embodiment, the value of the resistor P1104b1 is optimally 100 [Ω] to 2 [kΩ] for a panel of about 10 ′ ′ and 500 [Ω] for a large panel of 30 ′ ′ or more. 10 [kΩ] was optimal.

[0160]
【Effect of the invention】
As described above , according to the present invention , the use of a multi-electron beam source in which surface conduction electron-emitting devices are wired in a simple matrix as a large-area image display panel has been a hindrance to commercialization particularly at low cost. The row wiring drive circuit can drive an image display panel of a large area at low cost without ringing.

FIG. 2 is a timing diagram of a reference embodiment of the present invention.

FIG. 3 is a diagram showing the details of a PWM generator and a column wiring drive circuit according to a reference embodiment of the present invention.

FIG. 4 is a diagram showing details of a complementary switching circuit according to a reference embodiment of the present invention.

Claims (4)

It is used in an image display apparatus having a matrix image display panel having column wirings and row wirings and electron emitting elements connected to the column wirings and row wirings, and receives an output of a modulation signal modulated by a pulse width modulation circuit. A column wiring drive circuit that outputs a column wiring drive signal for driving an electron-emitting device connected to the column wiring, wherein
  A complementary switching circuit, and a resistance between the complementary switching circuit and the column wiring,
  In the first period corresponding to the change of the output of the modulation signal, a column wiring drive signal is output with an output impedance determined by the complementary switching circuit and the resistor,
  After the first period, the complementary switching circuit receiving the output of the modulation signal is controlled to output the column wiring drive signal to the column wiring with an impedance lower than the first period with respect to the column wiring. And a column wiring drive circuit. A matrix image display panel having column wiring and row wiring and an electron emitting element connected to the column wiring and row wiring, and output of a modulation signal modulated by a pulse width modulation circuit and connected to the column wiring An image display apparatus comprising: a column wiring drive circuit for outputting a column wiring drive signal for driving an electron emitting element;
  The column wiring drive circuit is
  A complementary switching circuit, and a resistance between the complementary switching circuit and the column wiring,
  In the first period corresponding to the change of the output of the modulation signal, a column wiring drive signal is output with an output impedance determined by the complementary switching circuit and the resistor,
  After the first period, the complementary switching circuit receiving the output of the modulation signal is controlled to output the column wiring drive signal to the column wiring with an impedance lower than the first period with respect to the column wiring. An image display apparatus characterized by further comprising: The path for outputting the column wiring drive signal with an impedance lower than the first period to the column wiring from the complementary switching circuit receiving the output of the modulation signal has the resistance between the path with the column wiring. 3. The image display apparatus according to claim 2, further comprising a path formed by shorting the resistor between the complementary switching circuit and the column wiring. The path for outputting the column wiring drive signal with an impedance lower than the first period to the column wiring from the complementary switching circuit receiving the output of the modulation signal has the resistance between the path with the column wiring. 3. The image display device according to claim 2, further comprising a path between the complementary switching circuit other than the complementary switching circuit and the column wiring.