1. A backlight modulation circuit comprising:
a first modulation section configured to generate a first backlight modulation signal;
a second modulation section configured to generate a second backlight modulation signal; and
a backlight modulation section configured to modulate illumination of a backlight module according to the first and second backlight modulation signals;
a signal processing section configured to transform external commands into a first and a second controlling signals, the first and second controlling signals being sent to the first and second modulation sections, respectively; and
wherein the backlight modulation circuit further comprises a first integration circuit, a second integration circuit, and a summing circuit, the first and second integration circuits carry out integration calculations on the first and second backlight modulation signals respectively and output a first and a second analog backlight modulation signals to the summing circuit, the summing circuit carries out a summing calculation with respect to the first and second analog backlight modulation signals and outputs a complex modulation signal to the backlight modulation section, and the backlight modulation section modulates illumination of the backlight module according to the complex backlight modulation signal.
2. The backlight modulation circuit of claim 1, wherein the first and second modulation sections generate the first and second modulation signals according to the first and second controlling signals, respectively.
3. The backlight modulation circuit of claim 1, further comprising an amplifying circuit, the amplifying circuit amplifying the analog backlight modulation signal from the first integration circuit and outputting an amplified first analog backlight modulation signal to the summing circuit.
4. The backlight modulation circuit of claim 3, wherein the signal processing section and the first and second modulation sections are integrated in a scaler.
5. The backlight modulation circuit of claim 4, further comprising a power supply circuit configured to provide electrical power to the scaler and the backlight modulation section.
6. The backlight modulation circuit of claim 1, wherein the backlight modulation section is an inverter.
7. The backlight modulation circuit of claim 1, wherein the backlight modulation section is a light emitting diode driving circuit.
8. The backlight modulation circuit of claim 1, wherein a minimum modulation range of the first backlight modulation signal exceeds that of the second backlight modulation signal.
9. The backlight module of claim 1, wherein a first integration section analyzes the first controlling signal to determine whether the first backlight modulation signal is beyond a modulation range of the backlight module, and selects a smaller one of the first backlight modulation signal and a maximum value of the modulation range of the backlight module as the first analog backlight modulation signal.
10. The backlight module of claim 1, wherein a second integration section analyzes the second backlight modulation signal to determine whether a modulation range of the second modulation signal is beyond a modulation range of the first integration section, and in response to the modulation range of the second modulation signal is beyond the modulation of the first integration signal, a difference value between a minimum value of the modulation range of the first integration section and the second backlight modulation signal is set as the second analog backlight modulation signal; and in response to the modulation range of the second modulation signal is not beyond the modulation range of the first integration signal, the second backlight modulation signal is set as the second analog backlight modulation signal.
11. A method for modulating illumination of a backlight module including a backlight modulation circuit, the backlight modulation circuit comprising a first modulation section, a second modulation section, and a backlight modulation section, the method comprising steps of:
generating a first backlight modulation signal from the first modulation section;
generating a second backlight modulation signal from the second modulation section;
transforming external commands into a first and a second controlling signals from a signal processing section and sending the first and second controlling signals to the first and second modulation sections, respectively;
carrying out integration calculations for the first and second backlight modulation signals respectively to obtain a first and a second analog backlight modulation signals, and carrying out a summing calculation for the first and second analog backlight modulation signals to obtain a complex modulation signal; and
modulating illumination of the backlight module from the backlight modulation section according to the complex modulation signal.
12. The method of claim 11, further comprising the step of generating the first and second modulation signals according to the first and second controlling signals from the first and second modulation sections, respectively.
13. The method of claim 11, further comprising amplifying the first analog backlight modulation signal output from the first integration circuit thereby generating an amplified first analog modulation signal, and transmitting the amplified first analog modulation signal to the summing circuit.
14. The method of claim 13, further comprising the step of providing electrical power for the scaler and the backlight modulation section from a power supply circuit.
15. The method of claim 13, wherein a minimum modulation range of the first backlight modulation signal is greater than that of the second backlight modulation signal.
16. The method of claim 11, wherein the step of carrying out integration calculations for the first and second backlight modulation signals comprises: the first modulation section analyzing the first controlling signal to determine whether the first backlight modulation signal is beyond a modulation range of the backlight module, and selecting a smaller one of the first controlling signal and a maximum value of the modulation range of the backlight module as the first analog backlight modulation signal.
17. The method of claim 11, wherein the step of carrying out integration calculations for the first and second backlight modulation signals comprises the second modulation section analyzing the second backlight modulation signal to determine whether a modulation range of the second modulation signal is beyond a modulation range of the first modulation section, wherein in response to the modulation range of the second modulation signal is beyond the modulation range of the first modulation signal, a difference value between a minimum value of the modulation range of the first modulation section and the second backlight modulation signal is set as the second analog backlight modulation signal; and wherein in response to the modulation range of the second modulation signal is not beyond the modulation range of the first modulation signal, the second backlight modulation signal is set as the second analog backlight modulation signal.
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 method of producing a mask blank, the method comprising:
a resist film forming process of dispensing a resist solution containing a resist material and a solvent onto a substrate that is substantially square in shape,
rotating the substrate to spread the dispensed resist solution over the substrate, and
drying the resist solution spread on the substrate, thereby forming a resist film on the substrate, wherein:
during the rotating step, a puddle of the resist solution is formed at an outer peripheral portion of the substrate while the substrate is rotated in the resist film forming process, the resist solution having a viscosity such that the puddle is drawn back towards a center of the substrate during the rotation of the substrate, and
an airflow is produced along an upper surface of the substrate from the center of the substrate towards the outer peripheral portion of the substrate, and is controlled in velocity and direction so as to suppress the puddle from moving towards the center because of the viscosity of the resist solution during the rotation of the substrate, and
wherein the resist film forming process includes a primary stage for rotating the substrate at a first rotation speed and a secondary stage for rotating the substrate at a second rotation speed lower than the first rotation speed.
2. A method of producing a mask blank, the method comprising:
a resist film forming process of dispensing a resist solution containing a resist material and a solvent onto a substrate that is substantially square in shape,
rotating the substrate to spread the dispensed resist solution over the substrate, and
drying the resist solution spread on the substrate, thereby forming a resist film on the substrate, wherein:
during the rotating step, a puddle of the resist solution is formed at an outer peripheral portion of the substrate while the substrate is rotated in the resist film forming process, the resist solution has a viscosity such that the puddle is drawn back towards a center of the substrate during the rotation of the substrate, and
an airflow is produced along an upper surface of the substrate from the center of the substrate towards the outer peripheral portion of the substrate and is controlled in velocity and direction so as to suppress the puddle from moving towards the center because of the viscosity of the resist solution during the rotation of the substrate;
a rotating condition of the substrate in the resist film forming process being changed in the middle of the resist film forming process so that a rotation speed of the substrate is different between a primary stage and a secondary stage of the resist film forming process;
the resist solution containing one of propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, and methyl isoamyl ketone as the solvent or as a main component of the solvent; and
the rotation speed of the substrate in the primary stage being 850-1900 rpm, a rotation time of the substrate in the primary stage being 1-5 seconds, the rotation speed of the substrate in the secondary stage being 100-450 rpm.
3. A method of producing a mask blank, the method comprising;
a resist film forming process of dispensing a resist solution containing a resist material and a solvent onto a substrate that is substantially square in shape,
rotating the substrate to spread the dispensed resist solution over the substrate, and
drying the resist solution spread on the substrate, thereby forming a resist film on the substrate, wherein:
a puddle of the resist solution is formed at an outer peripheral portion of the substrate while the substrate is rotated in the resist film forming process, the resist solution has a viscosity such that the puddle is drawn back towards a center of the substrate during the rotation of the substrate, and
an airflow is produced along an upper surface of the substrate from the center of the substrate towards the outer peripheral portion of the substrate and is controlled in velocity and direction so as to suppress the puddle from moving towards the center because of the viscosity of the resist solution during the rotation of the substrate;
a rotating condition of the substrate in the resist film forming process being changed in the middle of the resist film process so that a rotation speed of the substrate is different between a primary stage and a secondary stage of the resist film forming process; and
the resist solution containing ethyl lactate as the solvent or as a main component of the solvent, the rotation speed of the substrate in the primary stage being 850-2000 rpm, a rotation time of the substrate in the primary stage being 1-10 seconds, the rotation speed of the substrate in the secondary stage being 100-450 rpm.
4. The method of producing a mask blank according to any one of claims 1 through 3, wherein:
the resist is a chemically amplified resist.
5. The method of producing a mask blank according to any one of claims 2 and 3, wherein:
the rotation of the substrate at the rotation speed in the primary stage is followed by the rotation of the substrate at the rotation speed in the secondary stage.
6. The method of producing a mask blank according to any one of claims 1 through 3, wherein:
an unnecessary part of the resist film formed on the substrate is removed, the unnecessary part being located at the peripheral end portion of the substrate and not being involved in pattern formation.
7. The method of producing a mask blank according to any one of claims 1 through 3, wherein:
the substrate is a thin-film-coated substrate having a thin film formed on the substrate to function as a transfer pattern to be transferred to an object.
8. The method of producing a mask blank according to claim 7, wherein:
the thin film is made of a material containing chromium and at least one of oxygen and nitrogen.
9. A method of producing a transfer mask, wherein the thin film of the mask-blanks obtained by the method claimed in claim 7 is patterned to form, on the substrate, a mask pattern including a main pattern and an auxiliary pattern.
10. The method of producing a mask blank according to claim 2, wherein the primary stage includes a uniformly coating step of mainly forming the resist film having a uniform thickness by spreading the dispensed resist solution onto the substrate, the secondary stage includes a drying step of mainly drying the resist film, the rotation speed of the substrate in the uniformly coating step being 850-1900 rpm, the rotation time of the substrate being 1-5 seconds, the rotation speed of the substrate in the drying step being 100-450 rpm.
11. The method of producing a mask blank according to claim 3, wherein the primary stage includes a uniformly coating step of mainly forming the resist film having a uniform thickness by spreading the dispensed resist solution onto the substrate, the secondary stage includes a drying step of mainly drying the resist film, the rotation speed of the substrate in the uniformly coating step being 850-2000 rpm, the rotation time of the substrate being 1-10 seconds, the rotation speed of the substrate in the drying step being 100-450 rpm.
12. The method of producing a mask blank according to claim 1, wherein:
the resist solution has a viscosity of 1-10 mPa\xb7s,
the first rotation speed of the substrate in the primary stage is 850-2000 rpm,
a rotation time of the substrate in the primary stage is 1-10 seconds, and
the second rotation speed of the substrate in the secondary stage is 100-450 rpm.
13. The method of producing a mask blank according to claim 1, wherein:
the primary stage includes a uniformly coating step of mainly forming the resist film so as to have a uniform thickness, and
the secondary stage includes a drying step of mainly drying the resist film while maintaining the uniform thickness of the resist film.
14. The method of producing a mask blank according claim 1, wherein:
the air flow is generated from an opening located between the upper surface of the substrate and an upper portion of a cup by an exhausting member, the cup preventing the resist solution dispensed onto the substrate from splashing towards a surrounding area.
15. The method of producing a mask blank according to claim 14, wherein:
a velocity of the airflow colliding with the upper surface of the substrate and flowing towards the outer peripheral portion of the substrate is controlled by setting a distance from the upper surface of the substrate to the opening and an opening diameter of the opening.
16. The method of producing a mask blank according to claim 1, wherein:
the airflow colliding with the upper surface of the substrate has a velocity not lower than 0.5 msec and not higher than 5 msec.
17. The method of producing a mask blank according to claim 1, wherein:
the rotation of the substrate in the secondary stage is performed until the resist film reaches a state where no substantial variation in thickness occurs due to external factors except a thermal factor.
18. The method of producing a mask blank according to claim 1, wherein:
the substrate has a substrate size of 6 inch\xd76 inch, and
a resist film thickness uniformity is 100 \u212b or less in a critical area located at a center of the substrate within the resist film.
19. The method of producing a mask blank according to claim 1, wherein:
the substrate has a substrate size of 6 inch\xd76 inch, and
a difference between (1) a maximum thickness of the resist film inside a region of 140 mm\xd7140 mm, which is surrounding a region of 132 mm\xd7132 mm where a main pattern is to be formed, and (2) an average thickness of the resist film in the region of 132 mm\xd7132 mm is not greater than a half of the average thickness of the resist film in the region of 132 mm\xd7132 mm.