JP2003149426A - Color filter, method for manufacturing the same and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a color filter with high accuracy at a low cost. SOLUTION: A first cholesteric liquid crystal layer 20 has a reflection region Br for B color, a reflection region Gr for G color, while a second cholesteric liquid crystal layer 30 has a reflection region Br for B color and a reflection region Rr for R color. Each reflection region is formed by using a photomask so as to control the quantity of irradiation light. Since the common reflection region in the first and second cholesteric liquid crystal layers 20, 30 consists of the reflection region Br for the B color having the smallest quantity of irradiation light, the photomask can be shared.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color filter provided with a liquid crystal having cholesteric regularity suitable for color display, a method for manufacturing the same, and a display device.

[0002]

2. Description of the Related Art Conventionally, a multicolor display panel, a color filter, a polarizing element and the like using a liquid crystal having cholesteric regularity (hereinafter referred to as cholesteric liquid crystal) have been known. In the cholesteric liquid crystal, liquid crystal molecules are arranged in a spiral shape, and the wavelength of reflected light is determined according to the spiral pitch (distance in which the direction of the liquid crystal molecules makes one rotation). When cholesteric liquid crystal is used as a color filter in a transmissive liquid crystal display device, there is an advantage that light from a backlight is not absorbed and an effect of improving brightness is obtained.

As a kind of cholesteric liquid crystal,
Some contain a photoreactive chiral compound. A chiral compound is a material that adjusts the helical pitch of liquid crystal molecules, and in particular, a photoreactive chiral compound can change the helical pitch by irradiating light with a certain wavelength.

A method for producing a color filter using a cholesteric liquid crystal containing such a photoreactive chiral compound is disclosed in Japanese Patent Laid-Open No. 2001-242315. In this manufacturing method, the cholesteric liquid crystal has a two-layer structure, and when forming each layer, the amount of reflected light is adjusted by using a photomask to form a desired pattern.

[0005]

However, the above-mentioned manufacturing method does not disclose the relationship between the photomask used for forming the first layer and the photomask used for forming the second layer. .

The present invention has been made in view of this point, and a color filter manufacturing method capable of easily manufacturing a color filter by using a common photomask, and such a method. It is an object of the invention to provide a color filter having a structure suitable for a manufacturing method.

[0007]

[Means for Solving the Problems] The present invention provides the following inventions in order to achieve the above objects.

The method for producing a color filter according to the present invention comprises a liquid crystal having a cholesteric regularity, the composition of which changes according to the irradiation time and changes the wavelength of reflected light when irradiated with light of a specific wavelength. As a first step of forming a photomask on a substrate as a light source, and a photomask in which a light-shielding region that shields at least a certain amount of light of the specific wavelength is regularly formed with a predetermined width and the light source and the first layer. Between the second step and the third step of irradiating the light of the specific wavelength from the light source for a predetermined time, and cholesteric regularity, the irradiation time when the light of the specific wavelength is irradiated. The liquid crystal whose composition changes accordingly and the wavelength of the reflected light changes
A fourth step of forming a layer on the first layer, and a fifth step of disposing a photomask having substantially the same shape as the photomask used in the second step between the light source and the first layer. And a sixth step of irradiating the light of the specific wavelength from the light source for a predetermined time.

According to the present invention, the photomask used in the second step and the photomask used in the fifth step have substantially the same shape. Therefore, it is not necessary to prepare for designing different photomasks for each process, so that the manufacturing cost can be reduced.

Specifically, the photomask used in the second step and the photomask used in the fifth step may be masks having substantially the same shape but different shapes. When the manufacturing apparatus is configured by a line, different masks are used in the second step and the fifth step, but since these masks have substantially the same shape, they are created based on the same design data. Therefore, the manufacturing cost can be reduced.

The photomask used in the second step may be used as the photomask used in the fifth step. In this case, since the color filter can be manufactured using one photomask,
It is possible to significantly reduce the manufacturing cost.

Here, it is preferable that the liquid crystal of the first layer and the liquid crystal of the second layer are made of the same material, and the irradiation time of light in the third step and the irradiation time of light in the sixth step are different from each other. . This makes it possible to form regions that reflect light of different wavelengths in the first layer and the second layer, respectively.

Further, in the fifth step, the relative position of the photomask and the substrate is compared with the relative position of the photomask and the substrate in the second step, and the width of the light-shielding region is compared. When W is W, it is preferable to adjust so as to deviate by a natural number multiple of W. Since the wavelength of the reflected light is different between the region that shields the light of the specific wavelength and the region that does not shield the light, it is possible to form pixels with a pitch of width W. The same photomask is used, but temporarily
When two photomasks are used, the dimensional error of each photomask is accumulated and reflected in the pixel pitch error. However, according to the present invention, the pixel pitch error is
Since it is determined only by the relative positioning accuracy between the photomask and the substrate, a highly accurate color filter can be obtained. Further, when manufacturing a color filter of three colors, it is preferable that the relative positional deviation amount between the photomask and the substrate is W or 2W.

Further, the liquid crystal used in the first layer and the second layer has a property that the wavelength of the reflected light is less likely to change when irradiated with light having a wavelength different from the specific wavelength. It is preferable to provide a step of irradiating light having a wavelength that makes it difficult for the wavelength of the reflected light to change between the third step and the fourth step and after the sixth step. According to the present invention, since the first layer and the second layer can be manufactured by irradiation with light, steps such as cleaning with a solvent are unnecessary. Therefore, there is an advantage that the manufacturing facility can be simplified and a waste liquid treatment step is not required.

Further, the color filter according to the present invention is
A laminate of a first layer containing a liquid crystal and a second layer containing the liquid crystal, which has a cholesteric regularity and changes its composition depending on the irradiation time when the light of a specific wavelength is irradiated to change the wavelength of the reflected light. The first layer has a first region that reflects the first color and a second region that reflects the second color regularly arranged, and the second layer has the first color and the second region. A third region that reflects the same color and a fourth region that reflects the third color are regularly arranged, and the first color, the second color, and the third color
Among the colors, the first color is a color of reflected light obtained by irradiating the light of the specific wavelength for the shortest time or without irradiating the light of the specific wavelength.

Since this color filter reflects the first color in common in the first layer and the second layer, it is possible to form the first layer and the second layer using photomasks having substantially the same shape. Becomes Therefore, it is possible to reduce the cost and improve the accuracy of the color filter at the same time. Note that the color filter may be formed using two photomasks or the color filter may be formed using one photomask. Here, when the width of the first region is W, the width of the second region is 2W, the width of the third region is W, the width of the fourth region is 2W, and The second region of one layer is the third region of the second layer.
It is preferable that the second region is close to the region and the fourth region, and the fourth region of the second layer is close to the first region and the second region of the first layer.

Furthermore, the color filter described above may be applied to a display device. In the display device, since light is not absorbed by the color filter, it is possible to significantly improve the light utilization efficiency by guiding the reflected light to the color filter again.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION A structure of a color filter and a manufacturing method thereof according to an embodiment of the present invention will be described below. <1. Color filter structure>

FIG. 1 is a plan view of a color filter according to this embodiment. The color filter 1 is a transmissive filter and includes a plurality of sets of R pixels X1, B pixels X2, and G pixels X3. The R pixel X1 transmits R color light, the B pixel X2 transmits B color light, and the G pixel X3 transmits G color light. The R pixel X1, the B pixel X2, and the G pixel X3 are arranged in a stripe pattern.

FIG. 2 is a sectional view of the R pixel X1, the B pixel X2, and the G pixel X3. As shown in the figure, the color filter 1 includes a polyimide film 1 on the glass substrate 10.
It has a structure in which the first, the first cholesteric liquid crystal layer 20 and the second cholesteric liquid crystal layer 30 are laminated.

First cholesteric liquid crystal layer 20 and second
The cholesteric liquid crystal layer 30 contains a cholesteric liquid crystal. The cholesteric liquid crystal has a structure in which liquid crystal molecules are arranged in a spiral, and the wavelength band of reflected light is determined by the spiral pitch. Moreover, the cholesteric liquid crystal has a property of reflecting only one of the light circularly polarized counterclockwise or clockwise and transmitting the other.
The structure of the liquid crystal molecule determines which direction the circularly polarized light is reflected. Utilizing these properties, the first cholesteric liquid crystal layer 20 is provided with a G reflection region Gr that reflects G-color light circularly polarized in one direction and a B-color light circularly polarized in one direction. A B-reflecting region Br that reflects light is formed. On the other hand, the second cholesteric liquid crystal layer 30 has a B-reflecting region B circularly polarized in one direction.
An R reflection region Rr that reflects the R color light circularly polarized in one direction and r is formed. In the following description, the first cholesteric liquid crystal layer 20 and the second cholesteric liquid crystal layer 30 are supposed to reflect counterclockwise circularly polarized light in a predetermined band.

Therefore, when light which is circularly polarized counterclockwise from the lower portion of the color filter 1 enters, a part of the light is reflected by the first cholesteric liquid crystal layer 20 and the second cholesteric liquid crystal layer 30, and the rest of the light is reflected. It will be transparent.

Focusing on the R pixel X1, the G reflection region Gr is formed in the first cholesteric liquid crystal layer 20, and the B reflection region Br is formed in the second cholesteric liquid crystal layer 30. Therefore, in the R pixel X1, the light (counterclockwise circularly polarized light) incident from the lower portion of the glass substrate 10 is R
Only the color will be transparent. Focusing on the B pixel X2, the G reflection region Gr is formed in the first cholesteric liquid crystal layer 20 and the R reflection region Rr is formed in the second cholesteric liquid crystal layer 30, so that in the B pixel X2. As for the light (counterclockwise circularly polarized light) incident from the lower portion of the glass substrate 10, only the B color is transmitted. Furthermore, G pixel X3
Focusing on, since the B reflection region Br is formed in the first cholesteric liquid crystal layer 20 and the R reflection region Rr is formed in the second cholesteric liquid crystal layer 30, the glass substrate 10 of the G pixel X3 is formed. Light incident from the bottom (counterclockwise circularly polarized light) transmits only the G color.

Further, by providing the reflection plate below the glass substrate 10, the light reflected by the first cholesteric liquid crystal layer 20 and the second cholesteric liquid crystal layer 30 can be re-incident on the color filter 1. Therefore, according to this color filter, it is possible to improve the light utilization efficiency.

As described above, the color filter 1 of the present embodiment realizes a transmission type filter by combining the first cholesteric liquid crystal layer 20 and the second cholesteric liquid crystal layer 30.

Now, the first cholesteric liquid crystal layer 2
Comparing 0 and the reflective regions formed in the second cholesteric liquid crystal layer 30, the B reflective region Br is common.
When the pixel pitch of the color filter 1 is W, the width of the B reflection area Br is W. The common reflection area may be R color or G color, but it is particularly important to select a color area corresponding to B color in relation to the manufacturing method of the color filter.

First and second cholesteric liquid crystal layer 20
And 30 have the property that the spiral pitch changes according to the irradiation light amount of light of a certain wavelength, and the wavelength band of reflected light changes from a short wavelength to a long wavelength. This property is used to irradiate light with a specific wavelength when forming each reflection region, but a photomask is used to adjust the irradiation light amount.
A light shielding region is formed on the photomask. When the reflection regions of the first and second cholesteric liquid crystal layers 20 and 30 are formed using the same photomask, the photomask has a portion corresponding to the light shielding region as a common reflection region. As described above, the first and second cholesteric liquid crystal layers 20 and 30 reflect shorter wavelengths as the irradiation light amount is smaller. Further, the portion of the photomask corresponding to the light shielding region has the smallest irradiation light amount. Therefore, the first and second
The reflection area common to the cholesteric liquid crystal layers 20 and 30 is the B reflection area Br having the smallest irradiation light amount. In other words, the structure of the color filter 1 is selected in consideration of the manufacturing process so that the common reflection region can be formed with the smallest irradiation light amount.

<2. Color filter manufacturing method>

3 and 4 are process drawings for explaining the method of manufacturing the color filter. First, in the first step S1, a thickness of about 0.1 μm is formed on the glass substrate 10.
Then, the polyimide film 11 is provided so that the rubbing process is performed. The rubbing process is another process for aligning the liquid crystal molecules.

In the second step S2, the first cholesteric liquid crystal layer 20 is formed on the polyimide film 11. The material for the first cholesteric liquid crystal layer 20 is a nematic liquid crystal compound,
It contains a chiral compound having an optically active group, and may further contain a polymerizable monomer, a photopolymerization initiator, a surfactant, a gelling agent, a solvent and the like, if necessary.

In a preferred embodiment, the nematic liquid crystal compound (monomer) is 85% by weight and the chiral compound 14 is used.
% By weight, photoinitiator (Darocure 4265) 1
It consists of a 40 wt.% Toluene solution in which wt.% Is dissolved.

The following compounds may be mentioned as specific examples of the nematic liquid crystal compound. In the chemical formulas below, n represents an integer of 1 to 1000. Also,
Of course, the present invention is not limited to these nematic liquid crystal compounds.

[Chemical 1]

As the photoreactive chiral compound having both the chiral portion and the photoisomerization portion, the following compounds can be given as examples. When this photoreactive chiral compound is irradiated with ultraviolet rays having a wavelength of 365 nm,
The helical pitch of liquid crystal molecules can be changed according to the irradiation amount.

[Chemical 2]

In the second step S2, the above-mentioned material is applied to a thickness of 4
Then, spin coating is performed so as to have a thickness of μm, and heat orientation treatment is performed at 80 ° C. for 15 seconds. As a result, the first cholesteric liquid crystal layer 20 becomes a blue reflective layer that reflects light having a center wavelength of 460 nm.

Next, in the third step S3, the photomask M
A light source (not shown) and the first cholesteric liquid crystal layer 20.
And irradiation with ultraviolet rays having a wavelength of 365 nm at 0.2 J / cm 2 in the atmosphere, and then heat orientation treatment is performed at 50 ° C. for 60 seconds. The photomask M has a light-shielding region m1 having a width W.
And a transmissive area m2 having a width of 2 W. The light-shielding region m1 of this example hardly transmits ultraviolet rays having a wavelength of 365 nm, but shields ultraviolet rays having a wavelength of 365 nm at a constant ratio depending on the composition of the photoreactive chiral compound contained in the first cholesteric liquid crystal layer 20. May be

As described above, the photoreactive chiral compound forming the first cholesteric liquid crystal layer 20 has a wavelength of 365.
In response to ultraviolet rays of nm, the helical pitch of liquid crystal molecules is changed. Therefore, the wavelength range of the reflected light changes depending on the irradiation amount of the ultraviolet ray having the wavelength of 365 nm. Under the above-mentioned conditions, light having a wavelength of about 550 nm is reflected.

Now, the relationship between the pixels constituting the color filter and the photomask M will be described with reference to FIG. The color filter 1 of this example is a stripe type filter as shown in FIG. In addition, R shown in the figure
G and B represent the color of each pixel. And the third step S
3, the photomask M and the glass substrate 1 are arranged so that the light-shielding region m1 of the photomask M and the G color pixel are aligned with each other.
Adjust the relative positional relationship with 0. Specifically, the first
Glass substrate 10 on which cholesteric liquid crystal layer 20 is formed
Is placed on the XY table, and positioning is performed by moving the XY table.

Next, in a fourth step S4 shown in FIG. 3, ultraviolet rays having a wavelength of 405 nm are applied to the entire surface of the first cholesteric liquid crystal layer 20 at 1.5 J / cm 2 in a nitrogen atmosphere to cure the ultraviolet rays. Ultraviolet rays having a wavelength of 405 nm act as actinic rays, and polymerize or crosslink the liquid crystal molecules of the first cholesteric liquid crystal layer 20 to fix them. As a result, in the first cholesteric liquid crystal layer 20, the B reflection region Br that reflects the B color light and the G reflection region Gr that reflects the G color are formed. When the multicolor reflector was examined, the spectrum showed that the central wavelengths of the selective reflection wavelengths were 460 nm and 550 nm, the central wavelength was 460 nm in the B reflection region Br, and the central wavelength was 550 nm in the G reflection region Gr.

Next, in the fifth step S5 shown in FIG.
The toluene solution applied in the first step is applied again on the cholesteric liquid crystal layer 20 so that the film thickness becomes 4 μm.
The second cholesteric liquid crystal layer 30 is formed by performing a heat alignment treatment at 0 ° C. for 15 seconds. The second cholesteric liquid crystal layer 30 may be formed after forming a polyimide film on the first cholesteric liquid crystal layer 20 and performing a rubbing process.

In the sixth step S6, the photomask M used in the third step S3 is used again. At this time, the photomask M
The relative position between the substrate 10 and the substrate 10 is shifted by a distance W to the right or a distance 2W to the left with respect to the substrate 10 (color filter 1). That is, the relative position between the photomask M and the substrate 10 is displaced by the width of the light-shielding region m1 (width of the pixel pitch) or twice the width. Specifically, the relative positional relationship between the photomask M and the glass substrate 10 is adjusted so that the light-shielding region m1 of the photomask M and the G-color pixel match. Specifically, similarly to the third step S3, the glass substrate 10 is placed on the XY table, and the XY table is moved to perform positioning.

Then, after irradiating ultraviolet rays having a wavelength of 365 nm with 0.4 J / cm 2 in the atmosphere, a heat orientation treatment is carried out at 50 ° C. for 60 seconds. As a result, the photoreactive chiral compound reacts with ultraviolet rays having a wavelength of 365 nm to change the helical pitch of liquid crystal molecules. Under the above-mentioned conditions, light having a wavelength of about 650 nm is reflected.

Next, in the seventh step S7, ultraviolet rays having a wavelength of 405 nm are irradiated to the entire surface of the second cholesteric liquid crystal layer 30 at 1.5 J / cm2 in a nitrogen atmosphere to cure the ultraviolet rays. Ultraviolet rays with a wavelength of 405 nm act as actinic rays,
Liquid crystal molecules of the second cholesteric liquid crystal layer 30 are polymerized or crosslinked to be fixed.

The above is the method for manufacturing the color filter. According to this manufacturing method, it is possible to form the first cholesteric liquid crystal layer 20 and the second cholesteric liquid crystal layer 30 using the same photomask M.

In the manufacturing method described above, the first cholesteric liquid crystal layer 20 and the second cholesteric liquid crystal layer 30 were exposed using one photomask M. However, two photomasks having substantially the same shape were used. The exposure in the third step S3 and the sixth step S6 may be performed using each mask.
Even in this case, it is not necessary to separately design the two photomasks, and the photomasks can be created from the same image data or the like, so that the cost of the manufacturing equipment can be significantly reduced.

<3. Liquid crystal display>

Next, a display device using the above-mentioned color filter 1 will be described. FIG. 6 is a schematic configuration diagram showing a structure of a transmissive liquid crystal display device 1000 which is an example of a display device.

The light source 1100 emits white light having components in three wavelength bands. The three wavelength bands are about 650 nm
Is a red wavelength band centered at, a green wavelength band centered at about 550 nm and a blue wavelength band centered at about 460 nm. A reflector 1200 is provided behind the light source 1100 to guide the light emitted from the light source 1100 to the liquid crystal display device. Then, the light enters the circularly polarizing plate 1400 via the collimator 1300. Circularly polarizing plate 140 of this example
0 transmits light that is circularly polarized counterclockwise while absorbing light that is circularly polarized clockwise. Therefore, the circularly polarizing plate 1
The light emitted upward from 400 is circularly polarized light in the counterclockwise direction.

Here, the first cholesteric liquid crystal layer 20 and the second cholesteric liquid crystal layer 30 constituting the color filter 1 reflect the light in the predetermined wavelength band which is circularly polarized in the counterclockwise direction while transmitting the other light. Is configured. Therefore, when circularly left-handed circularly polarized light is incident from the lower portion of the color filter 1, the R pixel X1 outputs R-colored left-handed circularly polarized light, and the B pixel X2 outputs B-colored left-handed rotation. Circularly polarized light is emitted to the G pixel X
From G, the light circularly polarized in the left direction of G color is emitted.

Next, the first substrate 1500 is made of a transparent material such as glass, on which wirings such as scanning lines and data lines are formed in addition to thin film transistors and transparent electrodes. On the other hand, the second substrate 1700 is also made of a transparent material such as glass, and a common electrode is formed on the surface facing the first substrate 1500. A reference voltage is supplied to the common electrode. A liquid crystal layer 1600 is provided between the first substrate 1500 and the second substrate 1700. Liquid crystals have the property that the orientation of liquid crystal molecules changes depending on the applied voltage. A predetermined voltage is applied between the pixel electrode and the common electrode by controlling the on / off of the thin film transistor and the voltage supplied to the data line. Then, the thin film transistor is turned on to turn on the liquid crystal layer 16
When a voltage is applied to the liquid crystal layer 1600, the liquid crystal layer 1600 polarizes the incident light linearly (plane polarized light), while the thin film transistor is turned off and no voltage is applied to the liquid crystal layer 1600.
Does not linearly polarize incident light.

Also, a quarter of the upper surface of the second substrate 1700 is provided.
A λ plate 1800 and a linear polarization plate 1900 are provided. The 1/4 λ plate 1800 converts incident plane polarized light into circularly polarized light. In this example, counterclockwise circularly polarized light is obtained by the liquid crystal layer 1600 and the 1/4 λ plate 1800 to which the voltage is applied, while the liquid crystal layer 1600 and the 1/4 λ plate 1800 of the voltage are not applied. Circularly polarized light cannot be obtained depending on the set.

On the other hand, from the color filter 1 to the first substrate 1
The light emitted toward 500 is left-handed circularly polarized light. Therefore, while light is transmitted when the voltage is applied to the liquid crystal layer 1600, light is not transmitted when the voltage is not applied to the liquid crystal layer 1600. Thereby, the brightness can be adjusted for each pixel.

According to this transmission type liquid crystal display device 1000, the light reflected by the color filter 1 is reflected by the reflection plate 1200.
Since it can be reflected by and guided to the color filter 1 again, the utilization efficiency of light can be improved and a bright screen display can be realized. In addition, since the power consumption of the light source 1100 occupies a large portion of the entire transmissive liquid crystal display device 1000, it is possible to reduce the overall power consumption of the transmissive liquid crystal display device 1000 by using the color filter 1 described above. Become.

Such a transmissive liquid crystal display device 1000
Is suitable for a portable electronic device that receives power from a battery, and is preferably used for a mobile phone, for example.

The present invention is not limited to the above-described embodiments, but the above-described embodiments are exemplifications, and for example, the modifications described below are possible. In addition, anything having substantially the same configuration as the technical idea described in the claims of the present invention and exhibiting the same operational effect is included in the technical scope of the present invention. To be done.

[0055]

As described above, according to the present invention, a photomask can be commonly used in a color filter having a two-layer structure using cholesteric liquid crystal, so that the color filter can be used with high accuracy and at low cost. Can be manufactured.

[Brief description of drawings]

FIG. 1 is a plan view showing a structure of a color filter according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a partial cross section of the color filter.

FIG. 3 is a process drawing showing the method of manufacturing the same color filter.

FIG. 4 is a process drawing showing the method of manufacturing the same color filter.

FIG. 5 is a schematic diagram showing a relationship between pixels constituting the color filter and a photomask M.

FIG. 6 is a cross-sectional view showing a schematic structure of a transmissive liquid crystal display device using the same color filter.

[Explanation of symbols]

1 ... Color filter 10 ... Glass substrate 20 ... First cholesteric liquid crystal layer 30 ... Second cholesteric liquid crystal layer S1 to S7 ... First to seventh steps M ... Photo mask

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G02F 1/1335 505 G02F 1/1335 505 5G435 G09F 9/00 342 G09F 9/00 342Z 9/30 349 9 / 30 349B 9/35 9/35 F term (reference) 2H048 BA04 BA11 BA64 BB02 BB04 BB07 BB14 BB42 2H049 BA05 BA18 BA43 BB01 BB03 BC04 BC05 BC08 BC22 2H088 FA18 GA03 GA06 GA17 HA03 FA17 HA18 JA04 MA06 2H08X FA08 FA03 FA02 FA11 FA02 FA02 FA08 FA12Z FB02 FB12 FC01 FC23 FD04 FD06 GA06 HA06 LA12 LA15 LA30 5C094 AA43 BA43 CA24 ED03 GB10 5G435 AA04 AA17 BB12 BB15 CC12 GG12 KK05 KK07

Claims (9)

[Claims] 1. A method of manufacturing a color filter, wherein a liquid crystal having a cholesteric regularity, the composition of which changes with irradiation time of light having a specific wavelength and the wavelength of reflected light changes, is used as a first layer. Between the light source and the first layer, a first step of forming the photomask, and a photomask in which a light-blocking region that blocks at least a certain amount of light of the specific wavelength is regularly formed with a predetermined width is provided between the light source and the first layer. And a third step of irradiating the light of the specific wavelength from the light source for a predetermined time, and having a cholesteric regularity, and irradiating the light of the specific wavelength depending on the irradiation time. A fourth step of forming a liquid crystal whose composition changes and a wavelength of reflected light changes as a second layer on the first layer; and a photomask having substantially the same shape as the photomask used in the second step. With the light source Serial a fifth step of placing between the first layer, the sixth step and a method for manufacturing a color filter characterized by comprising a irradiating only the predetermined time the light of the specific wavelength from the light source. 2. The method of manufacturing a color filter according to claim 1, wherein the photomask used in the second step and the photomask used in the fifth step are masks having substantially the same shape and different shapes. . 3. The method for manufacturing a color filter according to claim 1, wherein the photomask used in the second step also serves as the photomask used in the fifth step. 4. The liquid crystal of the first layer and the liquid crystal of the second layer are made of the same material, and the light irradiation time in the third step and the light irradiation time in the sixth step are different. The method for producing a color filter according to claim 1. 5. In the fifth step, the relative position of the photomask and the substrate is compared with the relative position of the photomask and the substrate in the second step, and the width of the light shielding region is compared. The method of manufacturing a color filter according to claim 1, wherein the color filter is adjusted so as to deviate by a natural number multiple of W, where W is W. 6. The liquid crystal used in the first layer and the second layer has a property that the wavelength of the reflected light is less likely to change when irradiated with light having a wavelength different from the specific wavelength. The step of irradiating with light having a wavelength that makes it difficult for the wavelength of the reflected light to change is provided between the third step and the fourth step and after the sixth step. Color filter manufacturing method. 7. A first layer containing a liquid crystal and a second layer containing the liquid crystal, which have cholesteric regularity and whose composition changes according to the irradiation time to change the wavelength of reflected light when irradiated with light of a specific wavelength. In the color filter, the first layer has a first region that reflects a first color and a second region that reflects a second color, which are regularly arranged in the first layer. A third region that reflects the same color as the first color and a fourth region that reflects the third color are arranged regularly, and the first color, the second color, and the third color One color is a color of reflected light obtained by irradiating the light of the specific wavelength for the shortest time or without irradiating the light of the specific wavelength. 8. When the width of the first region is W, the width of the second region is 2W, the width of the third region is W, and the width of the fourth region is 2W. The second region of the first layer is adjacent to the third region and the fourth region of the second layer, and the fourth region of the second layer is the first region and the first region of the first layer. The color filter according to claim 7, wherein the color filter is close to two areas. 9. A display device comprising the color filter according to claim 7.