JP2007080754A - Lighting device and display device using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variable view angle lighting device and a display device. <P>SOLUTION: The display device includes an opening 7 to which light from a light source 1 passes through, a first optical sheet 4 having a region 6 for shielding light from the light source 1, and a second optical sheet 5 with a region 8 having a lens effect for aligning the light direction of light passed through the opening 7. The display device has means to move the first optical sheet 4 relative to the second optical sheet 5 so that the opening 7 of the first optical sheet 4 is placed in the position of the region 8 of the second optical sheet 5 having a lens effect, or in the position of the flat plane region of the second optical sheet 5 having no lens effect, and the means to move the opening 7 of the first optical sheet 4 relative to the second optical sheet 5 having a lens effect so that the focus position thereof being close or to become remote. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention mainly relates to an illuminating device, and in particular, the present invention relates to an illuminating device that varies the viewing angle characteristics of an emitted light beam using an optical structure and an actuating device.

  In many scenes such as the display field and the optical communication field, there is a demand for viewing angle control that aligns light beams spread to a certain extent in a certain direction.

  In order to meet such demands, illumination / display devices are widely used in which an optical sheet having a function of aligning incident light in a predetermined direction is provided on a light source and an exit of a housing surrounding the light source. For example, a prism sheet is used as the optical sheet. The prism sheet generally has a triangular prism shape or a kamaboko shape, and the traveling direction of the light beam is controlled by the prism effect or the lens effect. By using such an optical sheet in combination with a light source, it is possible to make an illumination / display device that controls the viewing angle, the light irradiation direction, and the brightness from the beginning.

  In recent years, there has been a growing demand to change the viewing angle characteristics depending on the situation. For example, if you work on a laptop computer on the Shinkansen, you may not want to be able to see confidential information from people in your next seat. In this case, a narrow viewing angle characteristic is required so that the liquid crystal screen of the notebook personal computer can be seen from the front, but is not visible when the angle is slightly increased. Further, when business activities are performed at a business trip destination, it is assumed that a situation occurs in which explanation is given while showing a liquid crystal screen to a customer. In this case, a wide viewing angle characteristic is required so that the liquid crystal screen of the notebook personal computer can be seen in a wide angle range. However, the notebook computer that is usually used does not have such a function, and only the viewing angle is controlled or only the brightness enhancement effect is controlled by attaching an optical sheet to the display. (Patent Document 1). In order to satisfy the requirements of both narrow viewing angle characteristics and wide viewing angle characteristics with a single notebook personal computer, an illuminating device and a display device that can arbitrarily switch viewing angle characteristics depending on the situation are required.

Japanese Patent Publication No. 7-7162

  As described above, the conventional illumination device and display device have a problem that the viewing angle characteristic cannot be arbitrarily used depending on the situation. An object of the present invention is to eliminate such drawbacks of the prior art and provide an illumination device and a display device with variable viewing angle characteristics.

  In order to achieve the above object, in an illuminating device and a display device including a light source and an optical sheet to which an optical structure having a function of controlling a light beam direction is added to light from the light source, the optical sheet includes at least The opening through which the light from the light source passes, the first optical sheet having a region that blocks the light from the light source, the light passing through the opening is transmitted, and the light beam direction of the transmitted light And a second optical sheet having a region having a flat surface that does not have the lens effect, and the opening position of the first optical sheet is the second optical sheet. And a position where the opening portion of the first optical sheet has a flat surface that does not have the lens effect of the second optical sheet. By having means for relatively horizontally moving the first optical sheet and the second optical sheet so that the states located in the regions can be created, the viewing angle characteristics of the lighting device and the display device can be arbitrarily set. It became possible to control.

  Alternatively, the position of the opening of the first optical sheet coincides with the focal point of the region having the lens effect of the second optical sheet or the collection region of the focal point, and the position of the opening of the first optical sheet. The first optical sheet and the second optical sheet are moved relatively vertically so that a state where the focal point of the lens effect region or the focal region of the focal point of the second optical sheet does not coincide can be created. By having the means for making it possible, the viewing angle characteristics of the illumination device and the display device can be arbitrarily controlled. Note that the vertical movement refers to movement in a direction in which two sheets are separated or in a direction in which the two sheets are brought closer to each other. There is no need for exactly two sheets to move in the vertical direction, and there is no problem even if they are separated in an oblique direction.

  FIG. 1 shows a typical configuration example of a lighting device of the present invention. The inner surface of the housing (2) that covers the light source (1) is made of a high reflectance member. A first optical sheet (4) and a second optical sheet (5) are provided at the light exit (3) portion of the housing (2). The first optical sheet (4) has, on the light incident side, a portion (6) that does not transmit light and exhibits a reflection effect, and an opening (7) that transmits light is provided in a part thereof. The light emitted from the light source enters the second optical sheet (5) through this opening. The second optical sheet (5) has a portion (8) showing a lens effect, and is designed so that its focal point is in the vicinity of the back surface of the sheet. Further, the second optical sheet (5) and the first optical sheet (4) are between two points of the focal position of the portion (8) showing the lens effect by the operating device (9) and a position away from the focal position. Can be moved. There is no problem even if the direction away from the focal position is perpendicular to the sheet surface, the horizontal direction, or the oblique direction.

  When the opening (7) of the first optical sheet (4) is at the focal position of the lens structure (8) of the second optical sheet (5), as shown in FIG. Most of the light incident from the opening (7) of the optical sheet (5) is incident on the lens structure (8) immediately above, and the optical axis is aligned in a certain direction. The light applied to the portion other than the opening (7) is reflected by the reflecting member of the housing (2) having a high reflectance or the reflecting portion (6) of the optical sheet (4), and repeatedly reflected several times. Later the opening (7) is reached. As a result, an illuminating device that emits light having strong directivity is obtained.

  When the opening (7) of the first optical sheet (4) is away from the focal position of the lens structure (8) of the second optical sheet (5), it is shown in FIG. (B) When the distance S is in the horizontal direction, as shown in FIG. 2 (c), the light emitted from the second optical sheet (5) is not aligned in one direction, and has a wide viewing angle. Become.

  In addition, when it is desired to keep the center luminance from changing even if the viewing angle characteristics are changed, such as for display applications, it is necessary to provide a mechanism for adjusting the power supplied to the lighting device to keep it constant. When moving in the horizontal direction for display applications, it is desirable to provide a surface with a small lens effect between the lens structures. Here, the surface having a small lens effect is a flat surface having no lens effect or a surface close to a flat surface, and even if there is some lens effect, it is a surface that can be considered as a flat surface. When there is no flat surface between the lens structure parts and in contact, the viewing angle is widened, but there is a risk that the brightness at the front will be low or discontinuous light directivity (a sudden darkening at a specific angle) may occur. is there.

  The actuating device may be any device that can control the positional relationship between the two optical sheets, and a piezoelectric element, an electromagnet, a motor, a spring, or the like is used.

  In this configuration example, only two optical sheets of the present invention are used at the light exit portion. For example, a commercially available diffusion plate is provided on the light incident side of the optical sheet, and a scattering sheet is provided on the light exit side. Thus, there is no problem even if a plurality of other optical sheets are used. Further, the surface in the text means an optical surface, and there is no problem even if a transparent protective film or the like is provided on the surface of the reflecting member.

  According to the present invention, when there is an opening of the first optical sheet at the focal position of the second optical sheet, the viewing angle luminance distribution is narrowed to a narrow angle range, and when viewed from the focal position, the viewing angle luminance distribution is wide. Become. Therefore, an illumination device and a display device that can control the viewing angle characteristics can be provided.

  Hereinafter, although the illuminating device and display apparatus concerning this invention are demonstrated based on figures, this invention is not limited to these embodiment at all.

Example 1
First, a lenticular lens sheet having a structure shown in FIG. 3 was prepared as a second optical sheet (5) by a hot embossing method. The molding material is acrylic with a refractive index of 1.5, the radius of curvature of the lenticular lens is 80 μm, the lens pitch is 200 μm, the flat part width between the lenses is 49.6 μm, and the thickness from the lens apex position to the back of the sheet is 210 μm. .

  In order to prevent light from passing through one side of a 50 μm-thick polyethylene terephthalate film as the first optical sheet (4) separately from the sheet, silver was formed by sputtering and an opening was provided by photolithography. The shape of the opening was a slit, and the opening width was 40 μm.

  These two optical sheets were installed above the light source as shown in FIG. The opening of the first optical sheet (4) can be varied using the actuator (9) at a focal position and a position shifted by 1 mm in the vertical direction from the focal position.

  As shown in FIG. 4A, the actuating device has a configuration in which an electromagnet (14) and a permanent magnet (11) are combined. A magnetic force is applied to the iron cores (12) and (13) by the electromagnet (14) to move the first optical sheet (4) up and down from the focal position of the lens sheet as the second optical sheet (5). When the position of the optical sheet is moved horizontally from the focal position of the lens sheet that is the second optical sheet (5), the relative difference between the opening position of the first optical sheet and the focal position of the lens sheet is Positioning can be accurately performed by the positioning guide (15) that determines the position when the relative difference becomes smaller. Once attached to one side, the position is held by the permanent magnet, so the power of the electromagnet may be turned off. The luminance characteristics of this lighting device were measured by changing the distance G. The measurement results are shown in FIG.

(Example 2)
As the second optical sheet (5), a lenticular lens sheet having the structure shown in FIG. 3 was prepared by hot embossing. The molding material is acrylic with a refractive index of 1.5, the radius of curvature of the lenticular lens is 80 μm, the lens pitch is 200 μm, the flat part width between the lenses is 49.6 μm, and the thickness from the lens apex position to the back of the sheet is 210 μm. .

  Separately from the sheet, silver was formed by sputtering on one side of a 50 μm-thick polyethylene terephthalate film as the first optical sheet (4), and an opening was provided by photolithography. The shape of the opening was a slit, and the opening width was 40 μm.

  These two optical sheets were installed in the opening of the housing as shown in FIG. Also on the inner surface of the housing, silver was formed by sputtering, and titanium oxide particles were dispersed and applied to the binder so as to diffusely reflect on the sputtered silver layer. The reflectance measured with an integrating sphere was 96%. The opening can be changed by using an actuator (9) at a position shifted by 1 mm in the vertical direction from the focal position.

  As shown in FIG. 4A, the actuating device has a configuration in which an electromagnet (14) and a permanent magnet (11) are combined. A magnetic force is applied to the iron cores (12) and (13) by the electromagnet (14) to move the first optical sheet (4) up and down from the focal position of the lens sheet as the second optical sheet (5). When the position of the optical sheet is moved horizontally from the focal position of the lens sheet that is the second optical sheet (5), the relative difference between the opening position of the first optical sheet and the focal position of the lens sheet is Positioning can be accurately performed by the positioning guide (15) that determines the position when the relative difference becomes smaller. Once attached to one side, the position is held by the permanent magnet, so the power of the electromagnet may be turned off. The luminance characteristics of this lighting device were measured by changing the distance G. The measurement results are shown in FIG.

(Example 3)
The brightness of the illuminating device is the same as that of the embodiment (1) except that the opening can be changed from the focal position to a position shifted by 100 μm in the direction perpendicular to the lens in the horizontal plane of the sheet by using the actuator (9). The characteristics were measured by changing the distance S. The actuating device moved the first optical sheet (4) left and right using a piezoelectric (piezo) element (16) as shown in FIG. 4 (b). The luminance characteristics of this lighting device were measured by changing the distance S. The measurement results are shown in FIG.

Example 4
First, as a second optical sheet (5), a microlens array sheet having a structure shown in FIG. 6 was produced by a hot embossing method. As the molding material, acrylic having a refractive index of 1.5 was used, the radius of curvature of the microlens was 45 μm, and the thickness from the lens apex position to the back of the sheet was 120 μm. The arrangement of the lenses was a hexagonal close-packed arrangement, and the shortest distance between the lens vertices (lens pitch) was 50 μm.

  Separately from the sheet, silver was formed by sputtering on one side of the sheet as the first optical sheet (4), and the opening shown in FIG. 7 was provided by photolithography. The shape of the opening was circular, and the opening diameter was 10 μm.

  These two optical sheets were installed in the opening of the housing as shown in FIG. Also on the inner surface of the housing, silver was formed by sputtering, and titanium oxide particles were dispersed and applied to the binder so as to diffusely reflect on the sputtered silver layer. The reflectance measured with an integrating sphere was 96%. The opening can be changed by using an actuator (9) at a position shifted by 1 mm in the vertical direction from the focal position.

  The actuating device was configured to be manually actuated as shown in FIG. When the button (18) is pushed and turned, it leaves the focal position, and when the button (18) is turned, it returns to the focal position by the leaf spring (17). When moving to the focal position, the position in the horizontal direction is also accurately positioned by the positioning guide (15). The luminance characteristics of this lighting device were measured by changing the distance G. (Fig. 13)

(Example 5)
First, a lenticular lens sheet having a structure shown in FIG. 3 was prepared as a second optical sheet (5) by a hot embossing method. The molding material is acrylic with a refractive index of 1.5, the radius of curvature of the lenticular lens is 80 μm, the lens pitch is 200 μm, the flat part width between the lenses is 49.6 μm, and the thickness from the lens apex position to the back of the sheet is 210 μm. .

  Separately from the sheet, silver was formed by sputtering on one side of a 50 μm-thick polyethylene terephthalate film as the first optical sheet (4), and an opening was provided by photolithography. The shape of the opening was a slit, and the opening width was 40 μm.

  These two optical sheets were installed in the opening of the housing as shown in FIG. Also on the inner surface of the housing, silver was formed by sputtering, and titanium oxide particles were dispersed and applied to the binder so as to diffusely reflect on the sputtered silver layer. The reflectance measured with an integrating sphere was 96%. The opening can be changed by using an actuator (9) at a position shifted by 1 mm in the vertical direction from the focal position.

  The drawing unit (19) in FIG. 9 may be any unit that is generally used as a display device that displays an image or video by irradiating light from a light source. Examples thereof include a liquid crystal panel. Here, a liquid crystal panel was installed on the optical sheet as a drawing unit (19).

  As shown in FIG. 4A, the actuating device has a configuration in which an electromagnet (14) and a permanent magnet (11) are combined. A magnetic force is applied to the iron cores (12) and (13) by the electromagnet (14) to move the first optical sheet (4) up and down from the focal position of the lens sheet as the second optical sheet (5). When the position of the optical sheet is moved horizontally from the focal position of the lens sheet that is the second optical sheet (5), the relative difference between the opening position of the first optical sheet and the focal position of the lens sheet is Positioning can be accurately performed by the positioning guide (15) that determines the position when the relative difference becomes smaller. Once attached to one side, the position is held by the permanent magnet, so the power of the electromagnet may be turned off. The luminance characteristics of this display device were measured by changing the distance G. (Fig. 14)

(Explanation of measurement results)
10 to 14 show the viewing angle dependence of the relative luminance of the manufactured lighting device. Data in which the light source power is fixed to the same value at a position shifted from the focal position is shown. When it is actually used for a display or the like, the light source power is adjusted so that the front luminance becomes substantially the same value.

  10-14, it can be seen that the viewing angle luminance distribution is narrowed to a narrow angle range when there is an opening at the focal position, and the viewing angle luminance distribution is widened away from the focal position.

  Therefore, it was found that the viewing angle characteristics can be controlled in the illumination device by following the modes of Examples 1 to 4 and the display device by following the mode of Example 5, respectively.

It is a schematic block diagram which shows an example of the illuminating device of this invention. It is explanatory drawing which shows the effect of this invention. It is sectional drawing which shows an example of the lenticular lens sheet used for this invention. It is a schematic block diagram which shows an example of the illuminating device of this invention. It is a schematic block diagram which shows an example of the illuminating device of this invention. It is the perspective view and sectional drawing which show an example of the micro lens array sheet used for this invention. It is sectional drawing which shows an example of the optical sheet used for this invention. It is a schematic block diagram which shows an example of the operating device of the illumination and the display apparatus used for this invention. It is a schematic block diagram which shows an example of the display apparatus used for this invention. FIG. 6 is a characteristic diagram illustrating an example of a relative luminance characteristic of the lighting device according to the first embodiment. It is a characteristic view which shows an example of the relative luminance characteristic of the illuminating device in Example 2. FIG. 10 is a schematic diagram illustrating an example of relative luminance characteristics of a lighting device in Example 3. It is the schematic which shows an example of the relative-luminance characteristic of the illuminating device in Example 4. FIG. FIG. 10 is a characteristic diagram illustrating an example of a relative luminance characteristic of a display device in Example 5.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light source 2 Housing 3 Light emission port 4 1st optical sheet 5 2nd optical sheet 6 Structure part which shows reflection effect 7 Opening part which permeate | transmits light 8 Part which shows lens effect 9 Actuator 10 Light source light 11 Permanent magnet 12 Iron core 13 Iron core 14 Electromagnet 15 Positioning guide 16 Piezoelectric element 17 Leaf spring 18 Button 19 Liquid crystal panel

Claims (10)

In an illuminating device including a light source and an optical sheet to which an optical structure having a light beam direction control function is added to light from the light source, the optical sheet has an opening through which at least light from the light source passes. And a first optical sheet having a region for blocking light from the light source, and a first region having a lens effect for transmitting the light passing through the opening and aligning the light beam directions of the transmitted light. A state in which the opening of the first optical sheet is located in a region having the lens effect of the second optical sheet, and the opening of the first optical sheet The opening portion of the first optical sheet and the second optical sheet are formed so that the states of the second optical sheet positioned in regions having flat surfaces that do not have the lens effect can be created, respectively. Lighting apparatus characterized by comprising a moving means for or release the focal position is relatively close region having a lens effect In an illuminating device including a light source and an optical sheet to which an optical structure having a light beam direction control function is added to light from the light source, the optical sheet has an opening through which at least light from the light source passes. A first optical sheet having a region that blocks light from the light source, a region having the lens effect of transmitting light that has passed through the opening, and aligning the light beam direction of the transmitted light, and the lens And a second optical sheet having a region having a flat surface that has no effect, and the opening of the first optical sheet is located in the region having the lens effect of the second optical sheet. And a state in which the opening of the first optical sheet is located in a region having a flat surface that does not have the lens effect of the second optical sheet. As described above, the lighting apparatus characterized by having a means for relatively horizontally moving the first optical sheet and the second optical sheet In an illuminating device including a light source and an optical sheet to which an optical structure having a light beam direction control function is added to light from the light source, the optical sheet has an opening through which at least light from the light source passes. And a first optical sheet having a region for blocking light from the light source, and a first region having a lens effect for transmitting the light passing through the opening and aligning the light beam directions of the transmitted light. The first optical sheet and the focal point or the focal area formed by the lens effect of the second optical sheet coincide with each other, and the first optical sheet. The first light is formed so that a state in which the opening of the sheet and the focal point generated by the lens effect of the second optical sheet or the focal point collecting region do not coincide with each other can be created. Lighting apparatus characterized by comprising means for relatively vertically moving the sheet and the second optical sheet In a display device having a light source and an optical sheet to which an optical structure having a control function of a light beam direction is added to light from the light source, the optical sheet has an opening through which at least light from the light source passes. And a first optical sheet having a region for blocking light from the light source, and a first region having a lens effect for transmitting the light passing through the opening and aligning the light beam directions of the transmitted light. A state in which the opening of the first optical sheet is located in a region having the lens effect of the second optical sheet, and the opening of the first optical sheet The opening portion of the first optical sheet and the second optical sheet are formed so that the states of the second optical sheet positioned in regions having flat surfaces that do not have the lens effect can be created, respectively. Display device characterized by having a moving means or released the focal position is relatively close region having a lens effect In an illuminating device including a light source and an optical sheet to which an optical structure having a light beam direction control function is added to light from the light source, the optical sheet has an opening through which at least light from the light source passes. A first optical sheet having a region that blocks light from the light source, a region having the lens effect of transmitting light that has passed through the opening, and aligning the light beam direction of the transmitted light, and the lens And a second optical sheet having a region having a flat surface that has no effect, and the opening of the first optical sheet is located in the region having the lens effect of the second optical sheet. And a state in which the opening of the first optical sheet is located in a region having a flat surface that does not have the lens effect of the second optical sheet. As such, display device characterized by having means for relatively horizontally moving the first optical sheet and the second optical sheet In an illuminating device including a light source and an optical sheet to which an optical structure having a light beam direction control function is added to light from the light source, the optical sheet has an opening through which at least light from the light source passes. And a first optical sheet having a region for blocking light from the light source, and a first region having a lens effect for transmitting the light passing through the opening and aligning the light beam directions of the transmitted light. A state in which the opening of the first optical sheet and the focal point of the region having the lens effect of the second optical sheet or the focal region of the focal point coincide with each other. The first optical sheet and the second optical sheet have the lens effect and the focal point or the focal point collecting region does not coincide with each other. Display device characterized by having means for relatively vertically moving the optical sheet and the second optical sheet 5. The display device and the illumination device according to claim 1, further comprising a housing that covers a periphery of the light source, and a surface on the light source side reflects light from the light source. Lighting device and display device. 5. An illuminating device and a display device, wherein a piezoelectric element is used as the moving means of the first and second optical sheets according to claim 1. An illuminating device and a display device, wherein an electromagnet is used as the moving means of the first and second optical sheets according to claim 1. 5. A lighting device and a display device, wherein a spring is used as the moving means of the first and second optical sheets according to claim 1.

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