WO2020009384A1 - Optical disc for fingerprint recognition sensor and optical filter comprising same - Google Patents

Abstract

The present invention relates to an optical disc capable of positioning a fingerprint recognition region in a screen of a display, and an optical filter comprising same. The optical disc according to the present invention comprises a light absorption layer, which transmits light in a green region of visible light to increase a fingerprint recognition rate and effectively absorbs light in a red region so as to suppress a phenomenon in which the fingerprint recognition region in the screen of the display appears in red.

Description

Optical disc for fingerprint sensor and optical filter including same

The present invention relates to an optical disc and an optical filter including the same, which can locate an area where a fingerprint is recognized in a screen of a display device.

As a security method for releasing a locked state of a smartphone, various methods such as fingerprint recognition and iris recognition have been introduced in the pattern input applied from the beginning. Among them, the method of inputting biometric information such as fingerprint recognition or iris recognition is preferred because it is difficult for others other than the person to access it, and the hiring is increasing.

Among the biometrics, in the early stage of fingerprint recognition, capacitive fingerprint recognition took the most part. The capacitive type has the advantage of good recognition rate and reliability as the condenser reacts to the fingerprint by the pressure of the bone of the fingerprint.

However, with the development of smartphones, the demand for wider use of smartphone screens is intensified, and as a result, more attempts to use the physical buttons located on the front panel as touch panels are no longer available. have. In order to use capacitive fingerprint recognition, a fingerprint sensor must be located separately from the display, which is inconsistent with the current trend of widespread use of smartphone screens.

The security method that reflects this demand is optical fingerprint recognition. Optical fingerprint recognition is limited to OLED, but can be positioned inside the display. In order to increase the recognition rate of the optical fingerprint sensor, a visible light transmission filter that transmits only a wavelength band of a light source used as signal light is required.

An object of the present invention is to provide an optical disc and an optical filter comprising the same that can be located in the screen of the display device fingerprint recognition site.

In order to solve the above object of the present invention,

The present invention in one embodiment,

Light transmissive substrates; And

It is formed on one or both sides of the base material, and includes a light absorbing layer comprising a resin binder and a light absorbing agent dispersed in the resin binder,

Provided are an optical disc for a fingerprint sensor having an average transmittance of 15% or less for light in a wavelength range of 620 nm to 710 nm.

In addition, the present invention in one embodiment,

The optical disc described above; And

It provides an optical filter comprising a selective wavelength reflecting layer formed on one or both surfaces of the optical disc.

Furthermore, the present invention in one embodiment,

Provided is a fingerprint recognition module comprising the optical filter described above.

The optical disc according to the present invention includes a light absorbing layer that transmits light in a green region of visible light to increase fingerprint recognition rate, and effectively absorbs light in a red region. Can be suppressed.

1 is a cross-sectional view showing a laminated structure of an optical disc according to an embodiment of the present invention.

2 is a cross-sectional view illustrating a laminated structure of an optical filter according to an embodiment of the present invention.

3 and 4 are cross-sectional views showing a laminated structure of the fingerprint recognition module according to an embodiment of the present invention.

5 is a result of comparing and observing the visibility of the optical filter for each wavelength band of the irradiated light.

6 is a graph of light absorption according to the wavelength of the optical disc.

7 is a light transmission graph according to the wavelength for the optical filter.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description.

However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

In the present invention, the terms "comprises" or "having" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

In addition, it is to be understood that the accompanying drawings in the present invention are shown to be enlarged or reduced for convenience of description.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings, and the same or corresponding components will be given the same reference numerals regardless of the reference numerals, and redundant description thereof will be omitted.

The present invention relates to an optical disc for a fingerprint sensor.

As a security method for releasing a locked state of a smartphone, various methods such as fingerprint recognition and iris recognition have been introduced in the pattern input applied from the beginning. Among them, the method of inputting biometric information such as fingerprint recognition or iris recognition is preferred because it is difficult for others other than the person to access it, and the hiring is increasing.

Among the biometrics, in the early stage of fingerprint recognition, capacitive fingerprint recognition took the most part. The capacitive type has the advantage of good recognition rate and reliability as the condenser responds to the fingerprint by the pressure of the bone of the fingerprint.

However, with the development of smartphones, the demand for wider use of smartphone screens is intensified, and as a result, more attempts to use the physical buttons located on the front panel as touch panels are no longer available. have. In order to use capacitive fingerprint recognition, a fingerprint sensor must be located separately from the display, which is inconsistent with the current trend of widespread use of smartphone screens.

The security method that reflects this demand is optical fingerprint recognition. Optical fingerprint recognition can be positioned inside the display. In order to increase the recognition rate of the optical fingerprint sensor, a visible light transmission filter that transmits only a wavelength band of a light source used as signal light is required.

Accordingly, the present invention provides an optical disc for a fingerprint sensor.

The optical disc for fingerprint recognition sensor according to the present invention includes a light absorbing layer that transmits light in the green region of visible light to increase the fingerprint recognition rate and effectively absorbs the light in the red region. Suppresses the appearance of color.

Hereinafter, the present invention will be described in detail.

Optical disc

The present invention in one embodiment,

Light transmissive substrates; And

It is formed on one or both sides of the base material, and includes a light absorbing layer comprising a resin binder and a light absorbing agent dispersed in the resin binder,

An optical disc for a fingerprint sensor having an average transmittance of 15% or less for light in a wavelength range of 620 to 710 nm is provided.

Optical disc for fingerprint recognition sensor according to the present invention, a light transmissive substrate; And a light absorbing layer including a light absorbing agent, wherein the light absorbing layer has an absorption maximum in the visible light region (550 nm to 750 nm), and the cut-off of the optical disc is 580 nm to 620 nm showing a red color in a 620 nm to 700 nm region. It absorbs light.

In one embodiment, the optical disc for fingerprint recognition sensor according to the present invention can reduce the phenomenon that the display looks red by absorbing a red region of the visible light to a certain range. Specifically, the optical disc has an average transmittance of 15% or less, 13% or less, 10% or less, or 7 to a wavelength in the wavelength range of 620 nm to 710 nm when the spectrophotometer measures the transmittance of the optical disc in the wavelength range of 300 nm to 1,200 nm. It may be expressed in% or less, and the average lower limit may be, for example, 1% or more or 3% or more. More specifically, the optical disc may have an average transmittance of 1% to 10% or 3% to 5% for light in a wavelength region of 620nm to 710nm.

In addition, the optical disc for a fingerprint sensor according to the present invention may satisfy the following condition 1.

[Condition 1]

10 <| T _10% -T _50% | <50 (nm)

T _50% represents the wavelength value at the point where light transmittance is 50% in the wavelength range of 550 nm to 710 nm,

T _10% represents the wavelength value at the point where the light transmittance is 10% in the wavelength range of 550 nm to 710 nm.

Specifically, the optical disc has a wavelength value (T _50% ) at a point where light transmittance is 50% in the wavelength range of 550 nm to 710 nm and a wavelength value (T _10% ) at a point where light transmittance is 10% in a wavelength range of 550 nm to 710 nm. The absolute value of the difference may be 50 nm or less, 40 nm or less, 30 nm or less, 25 nm or less, and the lower limit may be 10 nm or more or 15 nm or more.

Furthermore, the optical disc for fingerprint recognition sensor according to the present invention may have a light transmittance of 85% or more in the wavelength range of 430 nm to 560 nm when the spectrophotometer measures the transmittance of the optical disc in the wavelength range of 300 nm to 1,200 nm. Specifically, the light transmittance in the 430nm to 560nm wavelength region of the optical disc may be 85% or more, 88% or more, 90% or more, or 92% or more, the upper limit is 95% or less, 98% or less, 99% or less or 100%. Can be. More specifically, the light transmittance in the wavelength region of 430nm to 560nm of the optical disc may be 90% to 99% or 92% to 95%.

Hereinafter, each component of the optical disc according to the present invention will be described in more detail.

In the optical disc for fingerprint recognition sensor according to the present invention, as shown in FIG. 1, the optical disc 100 may have a structure in which the primer layer 120 and the light absorbing layer 110 are sequentially stacked on the light transmissive substrate 130. have. The primer layer 120 may be omitted. In addition, the light absorbing layer 110 is a structure in which a light absorbing dye that absorbs light in a red region of visible light is dispersed in a resin, and is also called a red absorbing layer. The light transmissive substrate 130 may be replaced with a resin substrate.

First, the optical disc for fingerprint recognition sensor according to the present invention includes a light transmissive substrate, and the light transmissive substrate is not particularly limited as long as it is transparent and a plate-shaped substrate, but specifically, a transparent glass substrate, a transparent resin substrate, or the like may be used. Can be.

Specifically, in the case of the transparent glass substrate as the light transmissive substrate, a commercially available transparent glass substrate can be used, and if necessary, a phosphate-based glass substrate containing copper oxide (CuO) can be used. In addition, in the case of a transparent resin substrate, any one having excellent strength can be used without particular limitation. For example, a light transmissive resin in which an inorganic filler is dispersed can be used, and a binder resin usable for the light absorbing layer can be used.

The transparent glass substrate may prevent thermal deformation and warpage according to an optical filter manufacturing process without inhibiting light transmittance of visible light, and the transparent resin substrate may include a light absorbing layer when the binder resin of the light absorbing layer is used as a transparent resin substrate. The degree of interfacial peeling can be improved by controlling the kind of the binder resin and the resin used as the light transmissive substrate in the same or similar manner.

In addition, the optical disc according to the present invention may include a light absorbing layer, and the light absorbing layer may be formed on one or both surfaces of the substrate, and may include a resin binder and a light absorbing agent dispersed in the resin binder.

The light absorbing layer has a spectrophotometer in the wavelength range of 300 nm to 1,200 nm, and the shortest wavelength (λ_cut-off) having a transmittance of 50% in a wavelength region longer than the 550 nm wavelength is measured in the range of 580 nm to 620 nm. exist. Specifically, the shortest wavelength (λ_cut-off) having a transmittance of 50% in the wavelength region longer than the 550 nm wavelength of the optical disc exists in the 590 nm to 610 nm wavelength region.

The light absorbing agent according to the present invention is a compound having a near infrared absorption maximum in the wavelength range of 650 nm to 700 nm, and absorbs light in the near infrared region incident to the optical filter to block light in the near infrared region from entering the image sensor. Do this.

In this case, the light absorbing agent is not particularly limited as long as the compound has a near infrared absorption maximum (λ _max ) in the wavelength range of 640 nm to 700 nm. It may include any one or more of a phosphorus dye and a dye having an absorption maximum of 680 ± 15 nm. For example, the dye may include SDA6698 (HW Sands, absorption peak 651 nm), SDA4451 (HW Sands, absorption peak 634 nm) and VIS680D (QCR Solutions, absorption peak 680 nm).

In addition, the light absorbing agent may be used alone, and in some cases, may be used in combination of three or more kinds or separated into two layers. In addition, the content of the light absorbing agent may be selected without limitation within a range that does not affect the light absorption of the optical disc. Specifically, it is 0.01-10.0 weight part with respect to 100 weight part of binder resin contained in a light absorption layer; 0.01 to 8.0 parts by weight; Or 0.01 to 5.0 parts by weight.

Next, the light absorbing layer according to the present invention may include a binder resin.

As said binder resin which concerns on this invention, a cyclic olefin resin, polyarylate resin, polysulfone resin, polyether sulfone resin, polyparaphenylene resin, polyarylene ether phosphine oxide resin, polyimide, for example Resins, polyetherimide resins, polyamideimide resins, acrylic resins, polycarbonate resins, polyethylene naphthalate resins, organic-inorganic hybrid series resins, and the like. Specifically, cyclic olefin polymer (cyclic olefin polymer, COP), cyclic olefin copolymer (cyclic olefin co-polymer, COC), polyimide resin (polyimide, PI) or a mixture thereof can be used.

Furthermore, the binder resin may further include an additive.

The additive may be used without particular limitation, as long as it can prevent modification of the light absorbing layer at a high temperature. For example, phenol (phenol) antioxidant, tin (Tin) stabilizer and the like, but is not limited thereto.

Optical filter

In addition, the present invention in one embodiment,

The optical disc described above; And

It provides an optical filter comprising a selective wavelength reflecting layer formed on one or both surfaces of the optical disc.

The optical filter according to the present invention may include a selective wavelength reflecting layer formed on one or both surfaces of the optical disc. Specifically, the optical filter includes a selective wavelength reflecting layer formed on both sides of the optical disc, and when measuring the transmittance of the optical filter in the spectrophotometer in the wavelength range of 300nm to 1,200nm 50% transmittance in the wavelength region longer than 550nm wavelength The shortest wavelength [lambda] _cut-off may be present in the 585 nm to 615 nm wavelength range. In addition, the longest wavelength (λ_cut-off) with a transmittance of 50% in a wavelength region longer than 550 nm when the spectrophotometer measures the transmittance of the optical filter in the wavelength range of 300 nm to 1,200 nm may exist in the 655 nm to 615 nm wavelength region. have.

In addition, the optical filter according to the present invention, when measuring the transmittance of the optical disc in the spectrophotometer in the wavelength range of 300nm to 1,200nm, the light transmittance in the wavelength range of 650nm to 1200nm may be 5% or less, 4% or less or 3% or less. And the average lower limit may be, for example, 0.5% or more or 1% or more.

Furthermore, the optical filter according to the present invention has a light transmittance of 90% or more, 93% or more, 95% or more or 97% in the wavelength range of 430 nm to 560 nm when the spectrophotometer measures the transmittance of the optical disc in the wavelength range of 300 nm to 1,200 nm. The upper limit may be 99% or less or 100%.

In addition, the optical filter according to the present invention may satisfy the following condition 1.

[Condition 1]

T _10% -T _50% | <50 (nm)

T _50% represents the wavelength value at the point where light transmittance is 50% in the wavelength range of 550 nm to 710 nm,

T _10% represents the wavelength value at the point where the light transmittance is 10% in the wavelength range of 550 nm to 710 nm.

Specifically, the optical filter has a wavelength value (T _50% ) at a point where light transmittance is 50% in the wavelength range of 550nm to 710nm and a wavelength value (T _10% ) at a point where light transmittance is 10% in the wavelength range of 550nm to 710nm. The absolute value of the difference may be 50 nm or less, 40 nm or less, 30 nm or less, 25 nm or less, and the average lower limit may be 5 nm or more or 10 nm or more.

Hereinafter, each component which comprises the optical filter which concerns on this invention is demonstrated more concretely.

In the optical filter according to the present invention, as shown in FIG. 2, the optical filter 200 includes an optical disc having a structure in which a primer layer 220 and a flaw layer 230 are sequentially stacked on a light transmissive substrate 230, First and second selective wavelength reflecting layers 240 and 250 are formed on and under the optical disc, respectively. The first and second selective wavelength reflecting layers 240 and 250 may have a structure in which TiO ₂ and SiO ₂ are alternately stacked.

First, the optical filter according to the present invention may include a selective wavelength reflecting layer on one or both surfaces of the optical disc.

Specifically, the selective wavelength reflecting layer may serve to reflect light in the near infrared region, and may have a structure such as a dielectric multilayer film in which a high refractive index layer and a low refractive index layer are alternately stacked, but is not limited thereto. In addition, the selective wavelength reflecting layer reflects light having a wavelength of 700 nm or more, specifically, a wavelength in the range of 700 nm to 1,100 nm, of light incident to the optical filter, thereby preventing the light in the range from entering the image sensor. , To prevent reflection of light in the visible light region in the wavelength range of 400 nm to 700 nm. That is, the selective wavelength reflecting layer may serve as an near-infrared reflecting layer (IR layer) reflecting near infrared rays and / or an anti-reflection layer (AR layer) for preventing visible light from being reflected. .

In this case, the selective wavelength reflecting layer may have a structure such as a dielectric multilayer film in which a high refractive index layer and a low refractive index layer are alternately stacked, an aluminum deposition film; Precious metal thin film; Alternatively, the method may further include a resin film in which one or more fine particles of indium oxide and tin oxide are dispersed. For example, the selective wavelength reflecting layer may have a structure in which a dielectric multilayer film having a first refractive index and a dielectric multilayer film having a second refractive index are alternately stacked, and the dielectric multilayer film having the first refractive index and the dielectric multilayer film having a second refractive index Refractive index deviation is 0.2 or more; 0.3 or more; Or 0.2 to 1.0.

Further, the high refractive index layer and the low refractive index layer of the selective wavelength reflecting layer is not particularly limited as long as the refractive index deviation of the high refractive index layer and the low refractive index layer is included in the above-described range, but specifically, the high refractive index layer is 2.1 to 2.5. It may include one or more selected from the group consisting of titanium oxide, aluminum oxide, zirconium oxide, tantalum pentoxide, niobium oxide, lanthanum oxide, yttrium oxide, zinc oxide, zinc sulfide and indium oxide having a refractive index of Indium oxide may further contain a small amount of titanium oxide, tin oxide, cerium oxide and the like. In addition, the low refractive index layer may include at least one member selected from the group consisting of silicon dioxide, lanthanum fluoride, magnesium fluoride, and sodium hexafluoride (Cryolite, Na ₃ AlF ₆ ) having a refractive index of 1.4 to 1.6.

Fingerprint Recognition Module

Furthermore, the present invention in one embodiment,

Provided is a fingerprint recognition module comprising the optical filter described above.

Fingerprint recognition module according to the present invention comprises the above-described optical filter; And a fingerprint recognition sensor on one surface of the optical filter. In this case, the fingerprint sensor may be a camera type or an optical type. Specifically, the fingerprint recognition module of the present invention includes the above-described optical filter (filter for fingerprint recognition sensor); It may include a fingerprint sensor and a circuit board for the fingerprint sensor. More specifically, the fingerprint recognition module may have a structure in which an optical filter, a fingerprint recognition sensor, and a circuit board for a fingerprint recognition sensor are sequentially stacked.

Specifically, the optical filter is a light transmissive substrate; And a light absorbing layer formed on one or both surfaces of the substrate and including a resin binder and a light absorbing agent dispersed in the resin binder.

It may include an optical disc for fingerprint recognition sensor that the light transmittance in the wavelength region of 620nm to 710nm is 15% or less on average.

More specifically, the optical filter includes the optical disc described above; And a selective wavelength reflecting layer formed on one or both surfaces of the optical disc.

As an example, in the fingerprint recognition module of the present invention, the optical filter may be a filter for a fingerprint sensor, and the fingerprint sensor including the optical filter may be located in an in display area of the display.

The fingerprint recognition module according to the present invention includes the optical filter as described above, thereby reducing the visibility of the red light to prevent the display screen from appearing red.

Display device

In addition, the present invention in one embodiment,

Provided is a display device including the fingerprint recognition module described above.

The display device according to the present invention may include a fingerprint recognition module in an in-display area of the display. In the present invention, the location of the fingerprint module in the in-display area of the display means that the fingerprint module is present in the light emitting area of the display panel, but is located opposite to the light emitting surface of the display panel. do.

As one example, the present invention can provide an OLED display device as shown in FIG. In detail, the OLED display device 300 may include a fingerprint recognition module 410 within the OLED display screen 400. More specifically, the OLED display device 300 includes an OLED display screen 400; And the fingerprint recognition module 410 described above under the OLED display screen 400. For example, the OLED display screen 400 has a structure in which the screen protective layer 310, the cover glass 320, and the OLED display panel 331 are sequentially stacked, and a fingerprint recognition module is disposed below the OLED display screen 400. 410 may be located. The fingerprint recognition module 410 has a structure in which an optical filter 340, a fingerprint recognition sensor 350, and a fingerprint recognition sensor circuit board 360 are sequentially stacked. The optical filter 340 may be a filter for a fingerprint sensor.

In addition, the present invention can provide an LCD display device as shown in FIG. In detail, the LCD display device 300 may include a fingerprint recognition module 410 in the area of the LCD display screen 400. More specifically, the LCD display device 300 includes an LCD display screen 400; And a fingerprint recognition module 410 under the LCD display screen 400. For example, the LCD display screen 400 may include a screen protective layer 310; LCD display panel 332; And a backlight unit 370 sequentially stacked, and includes a fingerprint recognition module 410 under the LCD display screen 400, wherein the fingerprint recognition module 410 is located at a portion where the backlight unit 370 is not applied. Can be located.

In addition, the fingerprint recognition module 410 may be located under the backlight unit 370. That is, the position of the fingerprint recognition module 410 is not limited to the position at which the backlight unit 370 is applied or not applied, and may be positioned differently according to the fingerprint recognition rate.

The fingerprint recognition module 410 has a structure including an optical filter 340, a fingerprint recognition sensor 350, and a circuit board 360 for a fingerprint recognition sensor.

Hereinafter, the present invention will be described in more detail with reference to Examples and Experimental Examples.

However, the following Examples and Experimental Examples are only illustrative of the present invention, and the content of the present invention is not limited to the following Examples and Experimental Examples.

Example 1

Light absorbers A, light absorbers B, and light absorbers C having absorption maxima in the wavelength ranges of 645 ± 5 nm, 670 ± 5 nm, and 685 ± 5 nm, respectively, were obtained commercially and mixed so as to be 0.5 to 5 parts by weight based on 100 parts by weight of the resin. . At this time, polymethyl methacrylate (PMMA) resin was used as the resin, and methyl ethyl ketone (MEK) was used as the organic solvent. Then, all the materials were put, and stirred for 24 hours or more with a magnetic stirrer to prepare a light absorption solution. The prepared light absorbing solution was applied to both surfaces of a glass substrate having a thickness of 0.2 mm, and cured at 120 ° C. for 50 minutes to prepare an optical disc including a light absorbing layer.

When the optical transmittance of this optical disc was measured using the spectrophotometer, it was confirmed that the wavelength which becomes Cut-off T _50% is 590 nm.

Example 2

First selection of the dielectric multilayer structure by alternately depositing SiO ₂ and Ti ₃ O ₅ on the first main surface of the optical disc prepared in Example 1 using an E-beam evaporator at 110 ± 5 ℃ A wavelength reflecting layer was formed. Subsequently, SiO ₂ and Ti ₃ O ₅ are alternately deposited on the second main surface of the optical article at an temperature of 110 ± 5 ° C. using an E-beam evaporator to form a second selective wavelength reflective layer having a dielectric multilayer structure. Was prepared. In this case, the number of laminated layers and the thickness of the stacked first and second selective wavelength reflecting layers are shown in Table 2 below. Here, the thickness means the total thickness of each of the first and second selective wavelength reflecting layers, and the unit is micrometer (μm).

	First Selective Wave Reflective Layer		Second Selective Wave Reflective Layer
	Floor Level [P1]	Thickness [D1]	Floor Level [P2]	Thickness [D2]
Example 2	20-25	2 ~ 3	20-25	2 ~ 3

Comparative Example 1

Light absorbers B and light absorbers C having absorption bands at wavelengths of 670 ± 5 nm and 685 ± 5 nm, respectively, were obtained commercially and mixed so as to be 0.5 to 5 parts by weight based on 100 parts by weight of the resin. At this time, polymethyl methacrylate (PMMA) resin was used as the resin, and methyl ethyl ketone (MEK) was used as the organic solvent. Then, all the materials were put, and stirred for 24 hours or more with a magnetic stirrer to prepare a light absorption solution. The prepared light absorbing solution was applied to both surfaces of a glass substrate having a thickness of 0.2 mm and dried at high temperature at 120 ° C. for 50 minutes to prepare an optical disc including a light absorbing layer.

When the optical transmittance of this optical disc was measured by a spectrophotometer, it was confirmed that the wavelength of Cut-off T _50% was 630 nm.

Comparative Example 2

Light absorbers C having an absorption maximum in each and the 685 ± 5 nm wavelength range were obtained commercially and mixed so as to be 0.5 to 5 parts by weight based on 100 parts by weight of the resin. At this time, polymethyl methacrylate (PMMA) resin was used as the resin, and methyl ethyl ketone (MEK) was used as the organic solvent. Then, all the materials were put, and stirred for 24 hours or more with a magnetic stirrer to prepare a light absorption solution. The prepared light absorbing solution was applied to both surfaces of a glass substrate having a thickness of 0.2 mm and dried at high temperature at 120 ° C. for 50 minutes to prepare an optical disc including a light absorbing layer.

When the light transmittance of this optical disc was measured by a spectrophotometer, it was confirmed that the wavelength of Cut-off T _50% was 650 nm.

Comparative Example 3

An optical filter was prepared by depositing a dielectric multilayer film in the same manner as in Example 2, except that the optical disc prepared in Comparative Example 1 was used as the optical disc.

Comparative Example 4

An optical filter was prepared by depositing a dielectric multilayer film in the same manner as in Example 2, except that the optical disc prepared in Comparative Example 2 was used as the optical disc.

Experimental Example 1

In order to determine the optical characteristics of the optical filter including the optical disc and the optical disc according to the present invention, the following experiment was performed.

First, the transmission spectra of the optical discs prepared in Example 1, Comparative Example 1 and Comparative Example 2 were measured at 0 ° incident angle using a spectrophotometer in the wavelength range of 350 nm to 1200 nm, and the results are shown in FIG. 5. It was.

In addition, light transmission spectra of the optical filters prepared in Example 2, Comparative Example 3, and Comparative Example 4 were measured, and the results are shown in FIG. 6, respectively.

In addition, the optical visibility of Example 2, Comparative Example 3, and Comparative Example 4, wherein the cut-off T _50% values of the optical discs were 590 nm, 630 nm, and 650 nm, respectively, was observed. Is shown in FIG. 7.

Referring to FIG. 5, the optical disc manufactured in Example 1 has a point where light absorption is 50% in a wavelength range of 580 nm to 610 nm, and the wavelength difference between a point where light absorption is 50% and a point where 10% is 25 nm is 25 nm. It can be seen that it is within. Specifically, when the light transmittance is measured, it can be seen that the wavelength which becomes Cut-off T _50% is 590 nm. On the other hand, in the optical discs prepared in Comparative Example 1 and Comparative Example 2, it can be seen that when the light transmittance is measured, the wavelengths of Cut-off T _50% are 630 nm and 650 nm, respectively. Through this, the optical disc according to the present invention can control the wavelength region of the absorbed light by controlling the light absorbing agent included in the light absorbing layer, thereby absorbing the near infrared wavelength.

In addition, referring to FIG. 6, the optical filter manufactured in Example 2 exhibits light transmittance of 80% or more in the wavelength region of 400 nm to 580 nm, and absorbs light in the wavelength region of 580 nm or more. On the other hand, the optical filter prepared in Comparative Example 3 shows a light transmittance of 80% or more in the wavelength region of 400nm to 630nm, it can be seen that the light in the wavelength region of 630nm or more absorb. In addition, it can be seen that the optical filter prepared in Comparative Example 4 exhibits light transmittance of 80% or more in the wavelength region of 400 nm to 650 nm, and absorbs light in the wavelength region of 650 nm or more. Through this, it can be seen that the optical filter according to the present invention effectively absorbs light in the red region compared with other optical filters.

Referring to Figure 7, the optical disc Cut-off T _50% embodiments apply the value to 590nm Example 2 of the optical filter of Comparative Example 3, an optical filter and an optical disc of applying the Cut-off T _50% value of the optical disc to 630nm It can be experimentally confirmed that the red visibility reflected by the optical filter is significantly reduced compared to the optical filter of Comparative Example 5, wherein the cut-off T _50% value is applied at 650 nm. Through this, the optical disc of the present invention includes a light absorbing agent absorbing a red region in the light absorbing layer, it can be seen that the red visibility of the optical filter including the optical disc is reduced.

Claims (14)

1. Light transmissive substrates; And

   Is formed on one or both sides of the base material, and includes a light absorbing layer comprising a resin binder and a light absorbing agent dispersed in the resin binder,

   An optical disc for a fingerprint sensor having an average light transmittance of 15% or less in a wavelength range of 620 nm to 710 nm.
2. The method of claim 1,

   When the transmittance of the optical disc was measured using a spectrophotometer in the wavelength range of 300 nm to 1,200 nm, the shortest wavelength (λ_cut-off) having a transmittance of 50% in the wavelength region longer than the 550 nm wavelength is present in the 580 nm to 610 nm wavelength region. Optical disc for fingerprint sensor.
3. The method of claim 1,

   Optical disc for fingerprint recognition sensor that satisfies the following condition 1:

   [Condition 1]

   10 <| T _10% -T _50% | <50 (nm)

   T _50% represents the wavelength value at the point where light transmittance is 50% in the wavelength range of 550 nm to 710 nm,

   T _10% represents the wavelength value at the point where the light transmittance is 10% in the wavelength range of 550 nm to 710 nm.
4. The method of claim 1,

   An optical disc for a fingerprint sensor having a light transmittance of 10% or less in a wavelength range of 640 nm to 710 nm when the transmittance of the optical disc is measured using a spectrophotometer in a wavelength range of 300 nm to 1,200 nm.
5. The method of claim 1,

   When the transmittance of the optical disc is measured using a spectrophotometer in the wavelength range of 300nm to 1,200nm optical transmittance of the fingerprint sensor in the wavelength range of 430nm to 560nm more than 85%.
6. An optical disc according to any one of claims 1 to 5; And

   And an optional wavelength reflecting layer formed on one or both surfaces of the optical disc.
7. The method of claim 6,

   And the selective wavelength reflecting layer is formed of a dielectric multilayer.
8. The method of claim 6,

   When the transmittance of the optical filter was measured using a spectrophotometer in the wavelength range of 300 nm to 1,200 nm, the shortest wavelength (λ_cut-off) having a transmittance of 50% in the wavelength region longer than the 550 nm wavelength is present in the 585 nm to 615 nm wavelength region. Optical filter.
9. The method of claim 6,

   Optical filter satisfying the following condition 2:

   [Condition 2]

   10 <| T _10% -T _50% | <50 (nm)

   T _50% represents the wavelength value at the point where light transmittance is 50% in the wavelength range of 550 nm to 710 nm,

   T _10% represents the wavelength value at the point where the light transmittance is 10% in the wavelength range of 550 nm to 710 nm.
10. The method of claim 6,

    An optical filter having a light transmittance of 5% or less in a wavelength range of 650 nm to 1200 nm when the transmittance of the optical filter is measured using a spectrophotometer in a wavelength range of 300 nm to 1,200 nm.
11. The method of claim 6,

    An optical filter having a light transmittance of 90% or more in a wavelength range of 430 nm to 560 nm when the transmittance of the optical filter is measured using a spectrophotometer in a wavelength range of 300 nm to 1,200 nm.
12. Fingerprint recognition module comprising an optical filter according to any one of claims 6 to 11.
13. OLED display panel; And

    An OLED display comprising a fingerprint recognition module according to claim 12 located below the OLED display panel.
14. LCD display panel;

    Backlight unit; And

    A fingerprint recognition module according to claim 12 located below the LCD display panel,

    The fingerprint recognition module is an LCD display located at a portion where the backlight unit is not applied.

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