WO2020032037A1

WO2020032037A1 - Optical-component retaining member

Info

Publication number: WO2020032037A1
Application number: PCT/JP2019/030934
Authority: WO
Inventors: 諭史清田; 和多田　一雄; 比嘉　剛久; 真宮　正道; 邦英四方
Original assignee: 京セラ株式会社
Priority date: 2018-08-08
Filing date: 2019-08-06
Publication date: 2020-02-13
Also published as: JPWO2020032037A1

Abstract

This optical-component retaining member is formed from an aluminum oxide-based ceramic containing an oxide of titanium represented by the composition formula TiO_2-x(1 ≤ x <2). The total content of Fe, Ni, Co, Mn, and Cr is 260 mass ppm or less.

Description

Optical component holding member

The present disclosure relates to an optical article holding member.

Patent Literature 1 describes Al ₂ O ₃ , Si, Ti, Mn, Fe, Cr, and the like as an example of the composition of a black ceramic. Fe, Cr, Co, It is described that Mn, Ni, Cu and the like are used.

JP-A-8-17388

A holding member for an optical article according to the present disclosure is made of an aluminum oxide ceramic containing an oxide of titanium represented by a composition formula of TiO _2-x (1 ≦ x <2), and includes Fe, Ni, Co, Mn, and Cr. The total content is 260 ppm by mass or less.

FIG. 1 is a schematic diagram illustrating a configuration of a lamp device including an optical component holding member according to an embodiment of the present disclosure, which is mounted on a front right side of a vehicle. FIG. 2 is a schematic diagram showing a configuration of a first sensor module arranged in the lamp device shown in FIG. FIG. 3 is a schematic diagram illustrating a configuration of a head-up display including an optical component holding member according to an embodiment of the present disclosure. FIG. 4 is a graph showing the measurement results of the reflectance in the example.

<Optical product holding member>
Hereinafter, an optical component holding member (holder) according to an embodiment of the present disclosure will be described in detail.
The holding member of the optical component of the present embodiment is made of an aluminum oxide ceramic containing an oxide of titanium represented by a composition formula of TiO _2-x (1 ≦ x <2), and includes Fe, Ni, Co, Mn, and Cr. Is 260 mass ppm or less. According to such a configuration, the reflectance is low over a wide wavelength range. In addition, the ultraviolet light (UV) absorption effect of the oxide of titanium can suppress deterioration due to sunlight, and can protect the held optical articles, thereby enabling long-term use. Further, when exposed to sunlight, the photocatalytic effect of the titanium oxide is exhibited, so that dirt around the optical article to be held can be removed and an antifouling effect can be obtained, so that the sensitivity of the optical article is maintained. Can be kept in a state. Hereinafter, the configuration of the optical component holding member of the present embodiment will be specifically described.

The aluminum oxide ceramics, of all components 100% by mass constituting the ceramics, aluminum oxide content in terms of Al to Al ₂ O ₃ is at that of the ceramic is 90 mass% or more. The oxide of titanium represented by the composition formula TiO _2-x (1 ≦ x < ₂ ) is obtained by reducing titanium oxide (TiO ₂ ). The crystal phase of the titanium oxide may be rutile type titanium oxide. Further, the total content of Fe, Ni, Co, Mn and Cr may be 170 mass ppm or less.

保持 The optical component holding member of the present embodiment has a black color having a sufficiently low reflectance for light in a relatively wide wavelength range. Specifically, the lightness index L * in the CIE1976L * a * b * color space is 48 or less, and the chromaticness indices a * and b * are -2 to 5 and -10 to 0, respectively. The value of the lightness index L * and the values of the chromaticness indices a * and b * in the CIE1976L * a * b * color space can be determined in accordance with JIS Z8722: 2009. For example, a spectral color difference meter (NF777 manufactured by Nippon Denshoku Industries Co., Ltd. or its successor) may be used, and the measurement conditions may be such that the light source is CIE standard light source D65 and the viewing angle is 2 °.

In the optical component holding member of the present embodiment, the maximum value Rmax of the reflectance over a wavelength range of 250 nm to 2500 nm is 24% or less, and the difference ΔR between the maximum value Rmax and the minimum value Rmin is 15.3% or less. . That is, the optical component holding member of the present embodiment has a low reflectance in the wavelength range of 250 nm to 2500 nm and a small variation in the wavelength distribution of the light intensity of the reflected light with respect to the irradiation light. The optical article holding member of the present embodiment has a uniform low reflectance over such a wide wavelength range.

In the optical component holding member of the present embodiment, the content of the titanium oxide represented by the composition formula of TiO _2-x (1 ≦ x <2) is, for example, of 100% by mass of all components constituting the ceramic. , 0.5 mass% or more and 4 mass% or less. When the content of the titanium oxide is in the above-described range, a black color having a low reflectance with sufficiently low saturation can be obtained, and the volume resistivity at room temperature (5 to 35 ° C.) can be reduced. It has electrical insulation of 10 ⁹ Ω · m or more. Further, from the viewpoint of further improving the insulation property, the volume specific resistance of the holding member for the optical article of the present embodiment may be, for example, 10 ⁸ Ω · m or more at 200 ° C. Normally, the volume resistivity decreases as the temperature increases, but the holding member for the optical article of the present embodiment has insulating properties even at a high temperature of 200 ° C. Here, the volume resistivity can be determined in accordance with JIS C 2141: 1992. The upper limit of the volume resistivity is not particularly limited.

保持 The holding member of the optical article need not contain aluminum titanate. When such a configuration is satisfied, since there is no aluminum titanate having a large difference in linear expansion coefficient with respect to aluminum oxide in the holding member, minute cracks are unlikely to occur even when the temperature is repeatedly increased and cooled. Whether an optical article holding member contains aluminum titanate or not may be determined by comparing an X-ray chart obtained using an X-ray diffractometer (XRD) with a JCPDS card (No. 00-041-0258). .

光学 In the optical component holding member of the present embodiment, the total content of Fe, Ni, Co, Mn and Cr is 260 mass ppm or less, that is, the content of Cr alone is 260 mass ppm at the maximum. When Cr is contained in alumina, light having a wavelength of 700 nm or more and less than 780 nm (hereinafter also referred to as short wavelength light) or light having a wavelength of 780 nm or more and less than 1590 nm (hereinafter referred to as long wavelength light) The optical component holding member of the present embodiment has a low Cr content, and thus has low reflectance in the short wavelength region and the long wavelength region.

(4) If the Cr content of the optical component holding member is 40 ppm by mass or less, the reflectance for light in a relatively wide wavelength range is sufficiently low.

Further, when the content of Fe in the holding member of the optical article is 100 ppm by mass or less, an increase in reflectance due to discoloration can be further suppressed, so that the reflectance in the visible light region and the (near) infrared region is reduced. Lower.

Further, if the content of Ni in the holding member of the optical article is 10 ppm by mass or less, the content of Co is 5 ppm by mass or less, or the content of Mn is 100 ppm by mass or less, changes in mechanical strength and electrical characteristics are caused. Becomes smaller.

The holding member of the optical article may include an oxide of silicon, calcium, and magnesium in a grain boundary phase that bonds the aluminum oxide crystal grains. Here, the total content of the oxides of silicon, calcium and magnesium is, for example, 2% by mass or more and 4% by mass or less of 100% by mass of all components constituting the ceramics. When the total content of the oxides of silicon, calcium and magnesium is 100% by mass, the content of the oxides of calcium and magnesium is 10% by mass or more and 30% by mass or less, and the balance is It may be an oxide of silicon. When the content of the oxides of silicon, calcium, and magnesium is within the above range, the holding member of the optical article has a volume resistivity at room temperature of 10 ¹¹ Ω · m or more, or 10 ¹² Ω · m or more.

結晶 Note that the crystal phase of the titanium oxide in the holding member of the optical article can be identified by XRD, and the value of x may be determined using a transmission electron microscope (TEM).

The contents of aluminum, silicon, calcium, magnesium, and titanium in terms of oxides were determined using an X-ray fluorescence spectrometer (XRF) or an inductively coupled plasma (ICP) emission spectrometer (ICP). Of Al ₂ O ₃ , SiO ₂ , CaO, MgO and TiO _2-x (1 ≦ x <2). The contents of Fe, Ni, Co, Mn, and Cr may be determined using a glow discharge mass spectrometer (GDMS).

Further, the aluminum oxide ceramics forming the holding member of the optical article is inexpensive, and has a high dielectric constant equivalent to that of high-purity and expensive aluminum oxide ceramics having a titanium oxide content of less than 0.1% by mass. Can be obtained.

The optical component holding member of the present embodiment may have a portion where the average value of the skewness Rsk is 0.04 or more and 0.45 or less. When the holding member of the optical article has such a portion, the reflectance is low. Note that the average value of all the skewnesses Rsk in the holding member of the optical article may be 0.04 or more and 0.45 or less.

保持 In addition, the optical component holding member of the present embodiment may have a portion where the average value of the Kurtosis Rku is 4.1 or more and 6.5 or less. When the holding member of the optical article has such a portion, the reflectance is low. The average value of all kurtosis Rku in the holding member of the optical article may be 4.1 or more and 6.5 or less.

Furthermore, the holding member of the optical article of the present embodiment may have a portion where the average value of the arithmetic average roughness Ra is 1 μm or more and 2 μm or less. When the holding member of the optical article has such a portion, the reflectance is low. In addition, the average value of all the arithmetic average roughnesses Ra in the holding member of the optical article may be 1 μm or more and 2 μm or less.

Skewness Rsk, Kurtosis Rku, and arithmetic average roughness Ra can be determined by using, for example, a laser microscope (VK-9510, manufactured by Keyence Corporation) in accordance with JIS B # 0601: 2001. The measurement conditions were as follows: the measurement mode was color super-depth, the measurement magnification was 400 times, the measurement range was 698 μm × 522 μm, the measurement pitch was 0.05 μm, the λs contour curve filter was 2.5 μm, and the λc contour curve filter was 0.08 mm. The average value of the measured values obtained from the eight measurement ranges may be the average value of the skewness Rsk, the Kurtosis Rku, and the arithmetic average roughness Ra.

The aluminum oxide ceramic may have a light-shielding surface, and the light-shielding surface may have a color difference Δ * Eab in the CIE1976L * a * b * color space of 4.5 or less.

The color difference Δ * Eab is an index indicating a variation in color tone, and is represented by the following equation (1).
ΔE * ab = [(ΔL *) ² + (Δa *) ² + (Δb *) ² ] ^1/2 (1)
(ΔL * is the difference between the lightness index L ₁ * of the first measurement target point on the light shielding surface and the lightness index L ₂ * of the second measurement target point, and Δa * is the chromaticness index of the first measurement target point on the light shielding surface. The difference between a ₁ * and the brightness index a ₂ * of the second measurement point, Δb * is the chromaticity index b ₁ * of the first measurement point on the light-shielding surface and the brightness index b ₂ * of the second measurement point. Is the difference.)

When the color difference Δ * Eab is within the above range, the variation in the color tone on the light-shielding surface is reduced, and the variation is hard to be visually recognized, thereby improving the commercial value.

The coefficient of variation of the lightness index L * in the CIE1976L * a * b * color space of the light-shielding surface may be 0.02 or less (excluding 0).

When the variation coefficient of the lightness index L * is within the above range, the light-shielding surface is hardly discolored even when repeatedly irradiated with light, so that it does not easily change over time. Here, the average value of the lightness index L * of the light-shielding surface is, for example, 48 or less.

The value of the lightness index L * and the values of the chromaticness indices a * and b * in the CIE1976 L * a * b * color space of the light-shielding surface can be obtained by the same method as described above.

アルミニウム Also, the aluminum oxide ceramic may have open pores, and a skewness of a circle equivalent diameter of the open pores may be 0.1 or more and 2 or less.

When the skewness of the equivalent diameter of the open pores is 0.1 or more, the distribution of the equivalent diameter of the open pores tilts to the smaller side, and floating metal powder or white light-colored powder enters the open pores. This makes it difficult to reduce the color tone on the light-shielding surface, thereby improving the commercial value.

平均 The average value of the equivalent circle diameter of the open pores is, for example, 4 μm or more and 6 μm or less. The porosity of the open pores is 3 area% or more and 6 area% or less.

To find the circle equivalent diameter and porosity of the open pores, first, the average particle diameter D ₅₀ was polished holding member in the cast iron plate with diamond abrasive grains of 3 [mu] m, an average particle diameter D ₅₀ 0. Polishing is performed on a tin platen using diamond abrasive grains of 5 μm to obtain a measurement surface.

Then, an average part of the measurement surface is selected and photographed with a CCD camera at a magnification of 100 using an optical microscope. Next, of the captured images, four areas having an area per area of 2.27 × 10 ² μm are set, and image analysis software (for example, Win ROOF, manufactured by Mitani Corporation) is used. By performing the analysis, it is possible to obtain the equivalent circle diameter and porosity of the open pores. In the analysis, the threshold value of the equivalent circle diameter of the open pores is 0.8 μm, and the equivalent circle diameter less than 0.8 μm is not analyzed.

歪 Then, the skewness of the circle equivalent diameter of the open pore may be obtained by using a function SKEW provided in Excel (registered trademark, Microsoft Corporation).

形状 The shape of the holding member for the optical article may be designed according to the shape of the optical article to be held, and is not particularly limited. In addition, examples of the optical component held by the holding member include an optical component included in a vehicle-mounted optical device.

(Manufacturing method of optical member holding member)
Next, an example of a method for manufacturing the optical component holding member of the present embodiment will be described.

First, powders of aluminum oxide, silicon oxide, calcium carbonate, magnesium hydroxide and titanium oxide are prepared.

合計 The total content of the powders of calcium carbonate, magnesium hydroxide, and silicon oxide is, for example, 6.5% by mass or more and 12.9% by mass or less of the total 100% by mass of the powder. The content of the powder of calcium carbonate, magnesium hydroxide and silicon oxide is 17.8% by mass or more and 53.4% by mass or less of the total of 100% by mass of these powders. The content of the magnesium hydroxide powder is 14.4% by mass or more and 43.2% by mass or less, and the remainder is silicon oxide powder.

The content of the titanium oxide powder is, for example, 0.5% by mass or more and 4% by mass or less of the total 100% by mass of each powder of aluminum oxide, silicon oxide, calcium carbonate, magnesium hydroxide, and titanium oxide; The balance is aluminum oxide powder.

Particularly, the content of magnesium hydroxide is preferably 30% by mass or more and 44% by mass or less of the content of titanium oxide. When the content of magnesium hydroxide is in the above range, generation of anorthite and mullite which are likely to occur in a reduction treatment described later is suppressed. Since anorthite and mullite have different average linear expansion coefficients from aluminum oxide, if the formation of these compounds is suppressed, the optical component holding member is used in an environment that is repeatedly exposed to heating and cooling. However, cracks are less likely to occur.

Then, these powders are wet-mixed by a pulverizer such as a barrel mill, a rotary mill, a vibration mill, a bead mill, an agitator mill, an atomizer, and an attritor to obtain a slurry. In the above-mentioned pulverization, a solvent, an organic binder such as polyvinyl alcohol (PVA) in an amount of 1 part by mass to 1.5 parts by mass with respect to 100 parts by mass of the solvent, and 0.1 part by mass with respect to 100 parts by mass of the solvent Parts by mass and 0.5 part by mass or less of the dispersant are put into the grinder together. Next, the obtained slurry is subjected to a demagnetization treatment and then spray-dried to obtain granules. By the demagnetization treatment, Fe, Ni and Co, which are ferromagnetic metals, are removed.

The content of Fe, Ni, Co, Mn and Cr in the holding member of the optical article is affected by the wear of the stainless steel member used in the crusher. For example, a stainless steel member that is worn by long-term use may be replaced with a titanium component that easily forms a passivation film on its surface, or a titanium-based film such as TiN, TiCN, TiC, TiAlN, TiAlCN, or TiAlO, or a non-titanium-based material. The surface of the stainless steel member may be coated with crystalline hard carbon (DLC). In addition to the demagnetization treatment, the replacement or coating of such a stainless steel member can provide an optical article holding member having a total content of Fe, Ni, Co, Mn and Cr of 260 mass ppm or less.

Then, the granules are molded by a dry pressure molding method or a cold isostatic pressing method (CIP) and then subjected to cutting to obtain a molded body. Thereafter, the obtained compact is fired in an air (oxidizing) atmosphere at a temperature of 1500 ° C. or higher and 1700 ° C. or lower for a predetermined period of time to obtain a sintered body.

Here, in order to obtain a holding member for an optical article in which the average pore diameter of the open pores has a skewness of 0.1 or more and 2 or less, the molding pressure may be, for example, 1500 MPa or more and 4000 MPa or less.

研削 After firing, grinding may be performed. Further, if necessary, a polishing may be performed by adjusting a polishing material, a vibration frequency and a polishing time using a vibration barrel polishing machine to obtain a predetermined surface property.

The sintered body obtained by the above-described method is used as a reducing atmosphere, for example, in a mixed gas having a nitrogen: hydrogen ratio of 87 to 90% by volume: 10 to 13% by volume, from 1300 ° C. to 1400 ° C. By holding (reducing treatment) at the above temperature for 1 hour or more and 2 hours or less, the optical component holding member of the present embodiment can be obtained.

To obtain an optical article holding member having a color difference Δ * Eab of 4.5 or less in the CIE1976L * a * b * color space of the light-shielding surface, the content of the titanium oxide powder is determined by changing the content of aluminum oxide, silicon oxide, , From 1.8% to 3% by mass of the total of 100% by mass of each powder of magnesium hydroxide and titanium oxide, and may be maintained at a temperature of 1,330 ° C to 1,400 ° C for 1 hour to 2 hours.

In order to obtain an optical article holding member in which the coefficient of variation of the lightness index L * in the CIE1976L * a * b * color space of the light-shielding surface is 0.02 or less (excluding 0), the content of the titanium oxide powder is required. To 1.8 mass% to 3 mass% of a total of 100 mass% of each powder of aluminum oxide, silicon oxide, calcium carbonate, magnesium hydroxide and titanium oxide, and 1 at a temperature of 1350 ° C to 1400 ° C. What is necessary is just to hold for more than time and less than 2 hours.

The optical article holding member of the present embodiment described above has low reflectance in the visible light region and the (near) infrared region, can be used for a long time, and can hold the optical article while maintaining its sensitivity. Therefore, for example, it can be used to hold an optical component included in a vehicle-mounted optical device.

<In-vehicle optical equipment>
Next, a lamp device and a head-up display will be described as an example of an in-vehicle optical device including the optical article holding member of the present embodiment, and the description will be sequentially given with reference to the drawings. However, in each drawing referred to below, for convenience of explanation, only a configuration necessary for describing the embodiment is simplified and shown. Therefore, the in-vehicle optical device according to the present disclosure may include any configuration that is not illustrated in the drawings referred to. Further, the dimensions of the components in the drawings do not faithfully represent the dimensions, dimensional ratios, and the like of the actual components.

(Lamp device)
In the following description, a configuration in which the lamp device is mounted on the right front of the vehicle will be described as an example, but the lamp device of the present disclosure is not limited to a configuration mounted on the right front of the vehicle as long as it has the function.

As shown in FIG. 1, a lamp device 20 according to an embodiment of the present disclosure includes a light-transmitting cover 21 located in a traveling direction of a vehicle, a housing 22 located on the opposite side of the light-transmitting cover 21, and a light-transmitting cover 21. And a headlight 24, a first sensor module 25, and a second sensor module 26 which are respectively located inside a lamp room 23 surrounded by the housing 22.

The headlight 24 includes an optical system component including at least one of a lens and a reflector. The light emitted from the headlight 24 passes through the translucent cover 21 and illuminates the right front of the vehicle. Since the lamp device 20 includes such a headlight 24, it functions as a headlight.

The first sensor module 25 includes a first substrate 251 (support member). The first substrate 251 supports a first visible light camera 252, a first LiDAR (Light Detection and Ranging) sensor 253, and a first light shielding member 254 (shielding member). Further, as shown in FIG. , A communication unit 256 and a power supply unit 257. The first substrate 251 is a substrate on which a sensor circuit including the first visible light camera 252, the first LiDAR sensor 253, the control unit 255, the communication unit 256, and the power supply unit 257 is mounted. That is, a plurality of sensors (the first visible light camera 252 and the first LiDAR sensor 253) having different detection methods, a first light-blocking member 254 which is a cylindrical hollow member surrounding these sensors, and a circuit for operating these sensors Are modularized on the first substrate 251.

よう As shown in FIG. 1, the first visible light camera 252 captures an image of the right side of the vehicle. That is, the first visible light camera 252 is a sensor that detects information on the right side of the vehicle.

(2) As shown in FIG. 2, the first LiDAR sensor 253 includes a light emitting unit 253a that emits infrared light and a light receiving unit 253b that detects reflected light that is reflected by the infrared light hitting an object present on the right side of the vehicle.

(1) The first LiDAR sensor 253 can calculate the distance to the object based on the time from emitting infrared light in a certain direction to detecting reflected light from the object. In addition, information on the shape of the object can be obtained by collecting and analyzing the measured values of the distance in association with the detected position. Further, information such as the material of the object associated with the reflection can be obtained based on the difference between the wavelengths of the emitted light and the reflected light. Further, information on the color of the target object (such as a white line on the road surface) can be obtained based on the difference in the reflectance of the reflected light. That is, the first LiDAR sensor 253 can obtain various information on the right side of the vehicle by a method different from that of the first visible light camera 252.

As shown in FIG. 1, the first sensor module 25 includes a first actuator 258 (an example of an adjustment mechanism) coupled to the first substrate 251. The first actuator 258 adjusts at least one of the position and the posture of the first substrate 251 with respect to the vehicle.

The second sensor module 26 includes the second substrate 261. The second substrate 261 supports the second visible light camera 262, the second LiDAR sensor 263, the millimeter wave radar 264, and the second light shielding member 265 which is a cylindrical hollow member surrounding these, all of which are not shown. The control unit, the communication unit, and the power supply unit are further supported.

The functions of the second visible light camera 262 and the second LiDAR sensor 263 are the same as the functions of the first visible light camera 252 and the first LiDAR sensor 253, respectively, and a description thereof will be omitted.

The millimeter-wave radar 264 includes a transmitting unit that transmits a millimeter wave and a receiving unit that receives a reflected wave that has been reflected by at least an object in which the millimeter wave hits the right front of the vehicle. The frequency of the millimeter wave is, for example, 24 GHz, 26 GHz, 76 GHz, or 79 GHz.

The millimeter-wave radar 264 can determine the distance to the object based on the time from when the infrared light is emitted in a certain direction to when the reflected light from the object is detected. In addition, by collecting and analyzing the distance measurement values in association with the detection position, information relating to the movement of the object can be obtained. That is, the millimeter wave radar 264 can obtain information on the right front of the vehicle by a method different from that of the second visible light camera 262 or the second LiDAR sensor 263.

The second sensor module 26 includes a second actuator 266 (an example of an adjustment mechanism) coupled to the second substrate 261. The second actuator 266 adjusts at least one of the position and the posture of the second substrate 261 with respect to the vehicle.

The lamp device 20 also includes a signal processing unit 27 located outside the lamp room 23. The signal processing unit 27 is configured to output a first drive signal 271 for driving the first actuator 258 and a second drive signal 272 for driving the second actuator 266. The first drive signal 271 includes at least one of the position and the posture of the first actuator 258, and the second drive signal 272 includes the information of at least one of the position and the posture of the second actuator 266. .

The lamp device 20 further includes the following configuration in addition to the configuration described above. That is, the lamp device 20 includes a light source element of the headlight 24 as an optical product, and further includes a light source element holding member that holds the light source element. In the lamp device 20, the light source element holding member of the headlight 24 is formed of the optical component holding member of the present embodiment. In other words, the optical component holding member of the present embodiment may be used for a light source element of a headlight. According to such a configuration, stray light can be removed by the low reflectance of the optical component holding member of the present embodiment, so that unnecessary reflection or scattering on the optical path can be reduced, and noise in the projected image is reduced. be able to. In addition, the UV absorption effect of the oxide of titanium can suppress deterioration due to sunlight, and can protect the light source element of the headlight 24, thereby enabling long-term use.

The lamp device 20 includes the lens and the glass of the first visible light camera 252 as optical components, and further includes a lens / glass holding member that holds the lens and the glass, respectively. Further, in the lamp device 20, the lens / glass holding member is formed of the above-described optical article holding member of the present embodiment. In other words, the optical component holding member of the present embodiment may be for a vehicle-mounted camera. According to such a configuration, noise of a projected image can be reduced by low reflectance in the visible light region and the (near) infrared region by the optical component holding member of the present embodiment. In addition, the photocatalytic effect of the oxide of titanium can prevent contamination near the lens and the glass and maintain the sensitivity.

The lamp device 20 includes, as optical components, a lens of the first LiDAR sensor 253, a light source element of the first LiDAR sensor 253, and a light receiving element of the light receiving section 253b of the first LiDAR sensor 253. As a holding member for holding, a lens holding member, a light source element holding member and a light receiving element holding member are provided. In the lamp device 20, at least one of the lens holding member, the light source element holding member, and the light receiving element holding member in the first LiDAR sensor 253 is made of the above-described optical component holding member of the present embodiment. In other words, the optical article holding member of the present embodiment may be for LiDAR. According to such a configuration, noise can be reduced by the low reflectance in the near-infrared region by the optical component holding member of the present embodiment, and as a result, the detection performance of the first LiDAR sensor 253 is enhanced. Further, the photocatalytic effect of the oxide of titanium can prevent contamination of the lens and the like in the first LiDAR sensor 253 and maintain the sensitivity.

The lamp device 20 includes an optical system component holding member that holds the above-described optical system component of the headlight 24. In addition, the lamp device 20 also includes the same optical components as those of the first visible light camera 252 and the first LiDAR sensor 253 described above, and a holding member for the second visible light camera 262 and the second LiDAR sensor 263. In the lamp device 20, the above-described optical component holding member, the holding members of the second visible light camera 262 and the second LiDAR sensor 263 may be configured by the holding member of the optical component of the present embodiment.

(Head-up display)
As illustrated in FIG. 3, the head-up display 30 according to the embodiment of the present disclosure includes an in-vehicle projector module 31, a reflection mirror 32, a microlens array 33, a convex lens 34, a combiner 35.

The vehicle-mounted projector module 31 projects an image in the direction of arrow a. The in-vehicle projector module 31 includes an optical and MEMS (Micro Electro Mechanical Systems) unit and an RGB light source module housed in the optical and MEMS unit.

The reflection mirror 32 reflects the image projected from the vehicle-mounted projector module 31 toward the microlens array 33. The micro lens array 33 functions as an intermediate image screen. The convex lens 34 is adjacent to the microlens array 33 and convex toward the combiner 35, and functions as a field lens. The combiner 35 reflects the image enlarged by the convex lens 34 toward the driver's eyes.

Here, the head-up display 30 further includes the following configuration in addition to the configuration described above. That is, the head-up display 30 includes a lens holding member that holds the lens of the vehicle-mounted projector module 31 and a lens holding member 36 that holds the microlens array 33 and the convex lens 34, as holding members for optical components.

In the head-up display 30, at least one of the lens holding member of the on-vehicle projector module 31 and the lens holding member 36 holding the microlens array 33 and the convex lens 34 is formed of the optical component holding member of the present embodiment. . In other words, the optical article holding member of the present embodiment may be for a head-up display. According to such a configuration, noise of a projected image can be reduced by a low reflectance in the visible light region by the optical component holding member of the present embodiment. Blue light can also be cut by the UV absorption effect of the oxide of titanium.

Although the embodiment according to the present disclosure has been described above, the present disclosure is not limited to the above-described embodiment, and it goes without saying that the present disclosure may be arbitrary without departing from the gist of the present disclosure.

For example, in the above-described embodiment, the case where the holding member of the optical article is used to hold the optical article included in the in-vehicle optical device has been described as an example. It is not limited to equipment, but can be used for other purposes. Other applications include, for example, semiconductor manufacturing equipment, electronic equipment, medical / physicochemical equipment, and the like. For example, it can be used to hold optical devices provided in a medical device such as a CT scan or an analyzer such as a transmission electron microscope (TEM). The use of the holding member for optical articles is not limited to the illustrated one.

Hereinafter, the present disclosure will be described in detail with reference to examples, but the present disclosure is not limited to the following examples.

First, powders of aluminum oxide, silicon oxide, calcium carbonate, magnesium hydroxide and titanium oxide were prepared.

The content of each powder of aluminum oxide, silicon oxide, calcium carbonate, magnesium hydroxide, and titanium oxide was adjusted so that the components constituting the sintered body, which is a holding member for optical products, had the values shown in Table 1. did.

Then, these powders were wet-mixed with a barrel mill and pulverized to obtain a slurry. In the pulverization, a solvent, 1.25 parts by mass of polyvinyl alcohol (PVA) with respect to 100 parts by mass of the solvent, and 0.3 part by mass of a dispersant with respect to 100 parts by mass of the solvent were also charged into the pulverizer. . Next, the obtained slurry was adjusted by demagnetization treatment so that the total content of Fe, Ni, Co, Mn, and Cr in the holding member of the optical product became a value shown in Table 1, and then spray-dried. Thus, granules were obtained. The stainless steel member used for the pulverizer was coated with a TiN film in advance, and then the powder was pulverized.

Then, the granules were formed by cold isostatic pressing (CIP) and then subjected to cutting to obtain a formed body. Thereafter, the obtained molded body was kept in an air (oxidizing) atmosphere at a temperature of 1570 ° C. for 2 hours to obtain a sintered body. Next, the surface of the sintered body was polished using a vibration barrel polishing machine.

Then, the sintered body obtained by the above-described method is kept at a temperature of 1350 ° C. for 1 hour and 30 minutes in a reducing atmosphere (a mixed gas having a nitrogen: hydrogen ratio of 88.5% by volume: 11.5% by volume). As a result, the sample No. 1-4 were obtained.

Each of the obtained samples was identified using XRD. The value of _x in TiO _2-x was determined using a transmission electron microscope (TEM). Further, the contents of the elements constituting each sample were determined using XRF, and converted into the identified components. Further, the contents of the trace components Fe, Ni, Co, Mn and Cr were determined using a glow discharge mass spectrometer (GDMS). Table 1 shows the results. Each sample contains inevitable impurities as components not shown in Table 1.

For each sample, the reflectance in the wavelength range of 250 nm to 2500 nm was determined using an ultraviolet-visible-near-infrared spectrophotometer (V-670, manufactured by JASCO Corporation), and the measured values were graphed. The results are shown in FIG. Further, ΔR was calculated from the minimum value Rmin and the maximum value Rmax of the reflectance in the above-mentioned region of each sample. Table 1 shows the minimum value Rmin, the maximum value Rmax, and ΔR of the reflectance.

Here, the integrating sphere unit used for the measurement of the reflectance is ISN-723, the reference light source is a deuterium lamp in a wavelength region of 250 nm to 360 nm, and the halogen lamp is a region in a wavelength range of 360 nm to 2500 nm. The mode was total reflectance, the data acquisition interval was 1.0 nm, the UV / Vis bandwidth was 5.0 nm, and the NIR bandwidth was 20.0 nm.

As shown in Table 1 and FIG. Sample Nos. 1 to 3 are sample Nos. Rmax and ΔR were smaller than 4. From these results, it was made of an aluminum oxide ceramic containing a titanium oxide represented by a composition formula of TiO _2-x (1 ≦ x <2), and the total content of Fe, Ni, Co, Mn and Cr was 260 It was found that when the mass was ppm or less, the reflectance was low in the wavelength range of 250 nm to 2500 nm, and the variation in the wavelength distribution of the light intensity of the reflected light with respect to the irradiation light was small.

In particular, for sample no. No. 1 is more suitable for use as described above because the difference ΔR in the reflectance in the above-mentioned region is 6.2%.

For each sample, the volume resistivity at room temperature (20 ° C.) was determined according to JIS C 2141: 1992. The measurement results are as follows.
Sample No. 1:10 ¹¹ Ω · m
Sample No. 2:10 ¹² Ω · m
Sample No. 3:10 ¹² Ω · m
Sample No. 4:10 ¹⁰ Ω · m

In addition, although the total of the components shown in Table 1 for each sample is not 100% by mass, components other than the components shown in Table 1 are unavoidable impurities.

Reference Signs List 20 lamp device 21 translucent cover 22 housing 23 light room 24 headlight 25 first sensor module 251 first substrate 252 first visible light camera 253 first LiDAR sensor 253a light emitting unit 253b light receiving unit 254 first light blocking member 255 control unit 256 Communication unit 257 Power supply unit 258 First actuator 26 Second sensor module 261 Second substrate 262 Second visible light camera 263 Second LiDAR sensor 264 Millimeter wave radar 265 Second light blocking member 266 Second actuator 27 Signal processing unit 271 First drive signal 272 Second drive signal 30 Head-up display 31 In-vehicle projector module 32 Reflecting mirror 33 Micro lens array 34 Convex lens 35 Combiner 36 Lens holding member

Claims

An aluminum oxide ceramic containing an oxide of titanium represented by a composition formula TiO 2-x (1 ≦ x <2);
An optical article holding member having a total content of Fe, Ni, Co, Mn, and Cr of 260 mass ppm or less.
2. The optical component holding member according to claim 1, wherein the total content of the Fe, Ni, Co, Mn, and Cr is 170 mass ppm or less.
3. The optical component holding member according to claim 1, further comprising a portion having an average value of the skewness Rsk of 0.04 or more and 0.45 or less.
The optical component holding member according to any one of claims 1 to 3, further comprising a portion having an average value of the Kurtosis Rku of 4.1 or more and 6.5 or less.
The optical article according to any one of claims 1 to 4, wherein the aluminum oxide ceramic has a light-shielding surface, and the light-shielding surface has a color difference Δ * Eab in a CIE1976L * a * b * color space of 4.5 or less. Element.
The aluminum oxide ceramic has a light-shielding surface, and a coefficient of variation of a lightness index L * in the CIE1976L * a * b * color space of the light-shielding surface is 0.02 or less (excluding 0). A member for holding an optical article according to any one of the above.
The member for holding an optical article according to any one of claims 1 to 6, wherein the aluminum oxide ceramic has open pores, and the open pores have a skewness of a circle equivalent diameter of 0.1 or more.
(8) The optical component holding member according to any one of (1) to (7), which holds an optical component included in the vehicle-mounted optical device.