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JP-7855219-B2 - Lighting device

JP7855219B2JP 7855219 B2JP7855219 B2JP 7855219B2JP-7855219-B2

Inventors

  • 岡田 真文
  • 鈴木 延幸
  • 長谷川 誠

Assignees

  • 株式会社ジャパンディスプレイ

Dates

Publication Date
20260508
Application Date
20220304

Claims (10)

  1. A lighting device comprising a reflecting cylinder having a reflector inside, and a liquid crystal lens assembly having multiple liquid crystal lenses stacked on the emission side of the reflecting cylinder, The liquid crystal lens assembly is formed in a direction parallel to the emission surface of the reflecting cylinder and has a light-shielding film that defines the light emission region from the liquid crystal lens assembly. The lighting device is characterized in that the light-shielding film is composed of a black adhesive material that adheres the plurality of liquid crystal lenses to each other .
  2. The illumination device according to claim 1, characterized in that, when viewed in a planar view, the outer shape of the liquid crystal lens is rectangular and the emission area is circular.
  3. The lighting device according to claim 1, characterized in that the plurality of liquid crystal lenses consist of two lenses.
  4. The illumination device according to claim 1, characterized in that the plurality of liquid crystal lenses consist of four lenses.
  5. The lighting device according to claim 1, characterized in that the liquid crystal lens has a configuration in which liquid crystal is sandwiched between a first substrate and a second substrate, and the light-shielding film is a film formed on the surface of the first substrate or the second substrate opposite to the surface facing the liquid crystal.
  6. The lighting device according to claim 1, characterized in that the liquid crystal lens has a configuration in which liquid crystal is sandwiched between a first substrate and a second substrate, and the light-shielding film is a film formed on the liquid crystal side of the first substrate or the second substrate.
  7. The aforementioned liquid crystal lens has a configuration in which liquid crystal is sandwiched between a first substrate and a second substrate. The lighting device according to claim 1, characterized in that the first substrate and the second substrate are bonded together with a black sealing material, and the black sealing material also serves as the light-shielding film.
  8. The lighting device according to claim 1 , characterized in that, when viewed in a planar view, a transparent resin is formed between the plurality of liquid crystal lenses on the inside of the light-shielding film.
  9. The lighting device according to claim 1, characterized in that the reflecting mirror formed inside the reflecting cylinder is a parabolic mirror.
  10. The lighting device according to claim 1, characterized in that a light-shielding cylinder, whose interior is a light-absorbing layer, is positioned between the reflective cylinder and the liquid crystal lens assembly.

Description

This invention relates to a lighting device that is thin, has a narrow beam angle, and minimizes light leakage to the surrounding area. In lighting devices, for example, when intended for use as a spotlight, a light source with high directivity, i.e., a small beam angle, is required. Traditionally, such light sources have used parabolic mirrors to form parallel light. However, this type of light source requires depth, making it difficult to miniaturize or thin the lighting device. When lighting devices using the above-described light sources are made thinner, it becomes difficult to reduce the beam angle. Furthermore, this leads to the problem of stray light with a very large emission angle. There are cases where it is desirable to control the emitted light using a liquid crystal lens, but even in this case, control is difficult for stray light with a large emission angle. Patent Document 1 provides an example of using multiple stacked liquid crystal panels. Patent Document 2 describes a configuration in which liquid crystal lenses are used in various optical devices. Japanese Patent Publication No. 2008-47541WO2012/099127 A1 This is a cross-sectional view illustrating the operation of a lighting device using a reflecting tube with a parabolic mirror.This is a perspective view of Figure 1.Figure 1 shows the illuminance distribution of the light spot produced by the lighting device.This is a cross-sectional view illustrating the operation of a lighting device using a tall reflector tube.Figure 4 shows the illuminance distribution of the light spot produced by the lighting device.This is a cross-sectional view illustrating the operation of a lighting device that uses a light-shielding tube with an internal light-absorbing wall together with a reflecting tube.Figure 6 is a perspective view.Figure 6 shows the illuminance distribution of the light spot produced by the lighting device.This is a cross-sectional view showing the operation of the lighting device when multiple liquid crystal lenses are mounted on the configuration shown in Figure 6.Figure 9 is a perspective view.This is a cross-sectional view of Example 1.Figure 11 is a perspective view.This is a plan view of the liquid crystal lens of Example 1.This is a cross-sectional view of the liquid crystal lens of Example 1.Figure 11 shows the illuminance distribution of the light spot provided by the lighting device of Example 1.This is an example of a convex lens configuration using liquid crystal lenses.This is a perspective view of a two-element liquid crystal lens.This is an example of a concave lens configuration using liquid crystal lenses.This is a cross-sectional view of a liquid crystal lens.This is a plan view showing electrodes formed on a TFT substrate and a counter substrate in a liquid crystal lens.This is a schematic diagram illustrating an example of light control using four liquid crystal lenses.This is a plan view of the liquid crystal lens of Example 2.This is a cross-sectional view of the liquid crystal lens of Example 2.This is a plan view of the liquid crystal lens of Example 3.This is a cross-sectional view of the liquid crystal lens of Example 3.This is a plan view of the liquid crystal lens of Example 4.This is a cross-sectional view of Figure 26.This is a plan view of a liquid crystal lens according to another example of Example 4.This is a cross-sectional view of Figure 28.This is a plan view of Example 5.This is a cross-sectional view of Figure 30.This is a plan view of another example of Example 5.This is a cross-sectional view of Figure 32.This is a plan view of yet another example of Example 5.This is a cross-sectional view of Figure 34. Figure 1 is a cross-sectional view of a lighting device using a reflector tube 10 with a parabolic mirror inside, and Figure 2 is a perspective view thereof. The lighting devices in Figures 1 and 2 are, for example, floodlights for spotlights. In Figure 1, an LED 20, which is the light source, is positioned in the center of the bottom of the reflector tube 10. The diameter D1 of the light-emitting surface of the parabolic mirror inside the reflector tube 10 in Figure 1 is, for example, 6.5 mm, and the height H1 of the reflector tube is, for example, 4 mm. The light from LED 20 is divergent light with a wide beam angle characteristic. This divergent light is reflected by a parabolic mirror to form parallel light LL parallel to the optical axis. However, a certain range of light is not reflected by the parabolic mirror and is emitted externally. This light LD (hereinafter also referred to as emitted light) has a large angle with the optical axis and causes blurring of the light spot. Figure 2 is a perspective view of Figure 1. As shown in Figure 2, the light-emitting portion of the parabolic mirror inside the reflecting cylinder 10 is circular. The LED 20 is omitted in Figure 2. In Figure 2, the light reflected by the parabolic mirror becomes parallel light LL parallel to the optical axis, while