JPH11175001A - Variable image display body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the variable image display body which is seen equally in the day and night and also improved in visibility and readability in both the day and night. SOLUTION: This display body includes a display element which has display surfaces (101a to 101d) so that the display surfaces can be viewed from outside and a visible display surface constitutes at least part of an image surface and a housing which contains the display element in a freely movable state; and at least one of the display surfaces can be viewed from outside and held in a display state. The display surfaces (101a to 101d) are formed of retroreflection films having observation angle characteristics (having 0.2 to 50 cd.1um<-1> .m<-2> reflection luminance, measured by a method based on JIS Z 9112, at a 0 deg. angle of incidence and at a 10 to 20 deg. angles of observation).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of an external illumination type variable image display capable of freely changing a display image (color, character, design, etc.).

[0002]

2. Description of the Related Art There are the following prior arts relating to an externally illuminated image display. (1) Exterior Lighting System for Signs, etc. The exterior lighting system disclosed in Japanese Patent Application Laid-Open No. 8-49218 discloses a display body for displaying images (but not variable) of road signs, advertisements, and the like, and an image surface of the display body. And an external illuminator for illuminating, and the external illuminator is installed at a position away from the display. The external illuminator is installed such that the illumination light is incident at an irradiation angle (θ) of 0 to 30 ° over the entire range of the image plane, and the image plane is formed from a retroreflective sheet having a wide observation angle characteristic. Have been.
According to the external lighting system, for example, the visibility and readability of the road sign from the driver are improved, and the inspection and maintenance of the external lighting body are facilitated.

JP-A-8-49218 discloses a capsule lens type reflection sheet containing a plurality of beads as micro lenses as a retroreflective film having a wide observation angle characteristic for forming an image surface of the display. It also discloses that the beads preferably contain two or more beads with different refractive indices. However, there is no description of the difference between the refractive indices of two or more beads and the optimum range of their blending. In particular, no means (such as a range of reflection luminance at a predetermined observation angle, whiteness, and the like) for making the image look almost the same in both day and night is disclosed.

(2) Variable information display device JP-A-57-60370, JP-A-57-6037
In the variable information display device disclosed in Japanese Patent Publication No.
One or two permanent magnets having different directions are arranged in a substantially rectangular parallelepiped rotating display element having two display surfaces,
Inside the housing that rotatably houses the display element,
By providing a rotation drive unit composed of two electromagnets, and having the electromagnets gradually take on the S pole or the N pole, the element can be rotated to change the display surface. Also, a self-luminous type variable information display with a built-in LED is known, but in order to sufficiently enhance the visibility in the daytime, it is necessary to emit light during the daytime, requiring a relatively large amount of power and running costs. Relatively high.

[0005]

The patent publication which discloses the variable information display (2) can improve the visibility of nighttime images and the legibility of information such as characters included in the images. No specific means has been suggested for providing an externally illuminated type information display that looks almost the same both day and night.

Further, if the variable information display as described above is effectively combined with a retroreflective film, it is possible to improve nighttime visibility and legibility. However, in the case of a normal retroreflective sheet, the retroreflective sheet is irradiated with relatively strong directivity light such as headlights or spotlights for illumination, rather than the whiteness observed under daylight. There is a tendency that emphasis is placed on the characteristic reflection luminance. Therefore,
Under daylight, it is derived from the metallic reflection film and looks entirely grayish, while in the case of retroreflection at night, it looks relatively white and bright.

However, in an image variable type display used for a sign, an advertisement, and the like, the emphasis is placed on the design in the daytime, and it is desired that the display looks almost the same in both the daytime and the nighttime. SUMMARY OF THE INVENTION It is an object of the present invention to provide a variable image display which looks almost the same both day and night, and has improved visibility and legibility both day and night.

[0008]

In order to achieve the above object, the present invention provides the following variable image display: a) It has a plurality of display surfaces (101a to 101d) and displays the display surfaces. A display element (10) whose visible surface constitutes at least a part of the image surface (14) when the surface is visible from the outside; and b) a housing for movably housing the display element (10). 11) and the display element (10).
The variable image display (1) wherein at least one of the plurality of display surfaces is visible from the outside and can be held in a display state.
At least one of 1d) is formed of a retroreflective film having an observation angle characteristic (A) specified below: Variable image display: observation angle characteristic (A): JIS Z 9117 The reflection luminance measured by a method conforming to the method described above is 0.2 to 100 cd • in the range of an incident angle of 0 ° and an observation angle of 10 ° to 20 °.
lux ^-1 · m ^-2

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Variable image display The variable image display is, for example, shown in FIG. 1 (a perspective view of a display element), FIG. 2 (a cross-sectional view of the variable image display), and FIG. As shown in the enlarged sectional view), the display device has a display element (10) and a housing (11) for movably storing the display element (10).

The illustrated display element (10) has a substantially rectangular parallelepiped shape, and is provided with a through hole (13) along a rotationally symmetric axis in the longitudinal direction of the display element (10). Through hole (1
A rotation axis (12) is arranged in 3), and the display element (1)
0) is rotatably supported around its rotation axis (12) and is housed in a housing (11). The illustrated display body has a display element (1) for simplifying the following description.
0) is an example of only one.

The remaining four sides of the display element (10) through which the axis of rotation (12) does not pass provide four display surfaces (101a, 101b, 101c, 101d) respectively. That is, a retroreflective film (not shown) having the observation angle characteristic (A) is fixed to the four side surfaces, and the surface (reflective surface) of the retroreflective film is formed on the display surface (reflection surface). 101a, 101b, 101c, 10
1d). Details of the retroreflective film will be described later.

A substantially rectangular opening (111) is formed in the housing (11) so that an entire display surface can be visually recognized by an external observer.
When the viewer can view 1a) from the opening (111), the remaining display surfaces (for example, 101b, 101c,
01d) also functions as an enclosing box for concealment so that the observer cannot see it. That is, the four display surfaces (10
1a, 101b, 101c, and 101d), different images (including designs and characters) are drawn, respectively, and an image surface for displaying any one image when desired by the operator of the variable image display body. Can be configured.
Therefore, the observer changes the display image of the display, and observes a plurality of images on one image plane. In addition, as shown in FIG. 4, when the display body (1) includes a plurality of display elements (10), an aggregate of visible display surfaces of the respective elements constitutes the image plane (14).

The area of one display surface can be appropriately determined by the number and arrangement of display elements. For example, in the case of the display (1) as shown in FIG. 4, the range is 1 to 400 cm ² .
In this type of display, it is preferable to determine the number and arrangement of display elements in consideration of the image resolution and the viewing distance.

The display element (10) keeps any one display surface (for example, 101a) in a display state so that it does not move (the display element does not rotate) for a desired period when desired. be able to. In the example shown in FIGS.
The cross section of the through hole (13) of the display element (10) is substantially square, and the rotation axis (12) is a cylinder having a smaller cross sectional area. The diameter of the rotation shaft (12) is
The setting is made so that the display element (10) is not unnecessarily bent when supported. The diameter of the rotating shaft (13) is usually in the range of 2 to 50 mm, depending on the material.

The housing (11) is installed such that the rotation axis (12) is arranged substantially parallel to the ground, and the display element (10) rotates around the rotation axis (12). When one display surface (101a) of the display element (10) is in a display state in which it is visible from the opening (111) of the housing (11), as shown in FIG.
In the vicinity of one corner (131), two inner peripheral surfaces (1)
32a and 132b) are pressed against and contact the outer peripheral surface of the rotating shaft (12) by the weight of the display element (10). In this state, the inner peripheral surface (132) of the through hole (13)
a, 132b) and the outer peripheral surface of the rotating shaft (12) effectively prevent the rotation of the display element (10). Therefore, when any one display surface can be visually recognized from the outside, the display element (10) does not move, and the display surface can be maintained in a displayed state. In order to effectively increase the frictional force as described above, the entire inner peripheral surface of the through hole (13) is
It is preferable that an elastic friction member such as rubber is disposed on the entire outer peripheral surface of the rotating shaft (12). As such an elastic member, silicone rubber, fluorine rubber, or the like, which is excellent in weather resistance, wear resistance, and heat resistance, is preferable.

Further, the entire inner peripheral surface of the through hole (13) is coated with a material such as a magnetizable metal, and the rotating shaft (12) is magnetized only when it is desired to prevent rotation, and the magnet is attracted by the magnet. In order to prevent rotation, a rotating shaft (1
2) can also be formed. Alternatively, (i) the display element (10) has a magnet built therein, or at least the four side surfaces (the surface to which the retroreflective film is fixed) of the display element (10) are made of a material capable of being magnetized. And
(Ii) On the inner wall surface (112) of the housing (11),
Alternatively, an electromagnet may be disposed at a position where it can act on the display element (10) through the inner wall surface (112), and rotation can be prevented by the attraction of the electromagnet.

On the other hand, the rotation of the display element (10) as described above can be performed manually, or can be performed using a mechanical drive mechanism. Hereinafter, an example using such a driving mechanism will be described with reference to FIGS. As shown in FIGS. 5 and 6, the display element (10) is a substantially rectangular parallelepiped and has a permanent magnet (5) disposed therein. The permanent magnet (5) is disposed so as to be orthogonal to the two display surfaces (101a and 101c in FIG. 6) facing each other. The display element (10) is formed from a solid rectangular parallelepiped member usually made of plastic, and the magnet (5) is embedded therein. The strength of the magnet (5) is not particularly limited, but is usually in the range of 100 to 10,000 Gauss.

The four display surfaces (101a, 101a)
b, 101c, 101d) except for two sides (102,
The through holes as described above are formed in the direction connecting 103) (however, not shown for simplicity of the figure). Therefore, in the illustrated example, a similar through hole is formed in the magnet (5). The display element may be formed from a box-shaped member having a cavity therein so as not to hinder the fixing of the magnet (5). Each display surface (i.e., the surface of the retroreflective sheet) typically has four different images or portions of images (comprising colors, text, designs, etc.).

In response to the above configuration, the housing (11) of the variable image display (1) is movably disposed at a position where it can act on the built-in magnet (5). Having. The electromagnets (60, 61) are preferably fixedly mounted on a movably mounted support (7), as shown in FIGS. That is, the support (7) is connected to a driving device (such as a motor) via a drive transmission element (not shown), and the driving of the support (7) is controlled by the driving device.
Control of the electromagnet). In the illustrated example, the electromagnet includes a first electromagnet (60) and a second electromagnet (61) (the reason will be described later). The strengths of the electromagnets (60, 61) are not particularly limited, but those having the same strength as the built-in magnet (5) can be used.

Here, a procedure for rotating the display element so that the other display surface can be visually recognized from the state where the display surface A (101a) is arranged so as to be visible from the outside through the opening of the housing will be described. I do. First, the first electromagnet (60)
And the support element (7) is moved from top to bottom in the figure (FIG. 7). At this time, the built-in magnet (5) arranged with the S pole facing the display surface (101c) side repels the S pole of the first electromagnet (60) approaching the display element (10), and the display element ( 10) rotates clockwise on the drawing (FIG. 7). When the display element (10) is rotated by approximately 180 °, the display element (10) is rotated.
The S pole of the first electromagnet (60) stopped at substantially the same height as the center in the vertical direction and the N pole of the built-in magnet (5) attract each other, and the display surface (101c) enters a display state (FIG. 8). ). At this time, even if the supply of current to the first electromagnet (60) is stopped, the above-mentioned holding mechanism (combination of a through hole with a rectangular cross section and a rotating shaft capable of frictionally contacting the inner peripheral surface thereof) acts as described above. ,
The display surface (101c) is kept in the display state. 7 and 8, the support for the electromagnet is omitted.

On the other hand, to display the display surface (101b), the second electromagnet (61) is used from the state of FIG. 8 (see FIGS. 9 to 11). As a continuation of the above operation, the support base (7)
Is moved further downward, the first electromagnet (60) from which the current supply is stopped is moved away from the display element (10), and the second electromagnet (61) is brought closer this time. At this time, the second electromagnet (61)
When the side of the display element (10) is set to the N pole,
The N pole of the built-in magnet (5) repels it, and the display element (1)
0) starts clockwise rotation (state of FIG. 9). Display surface (101d) of display element (10) that has started to rotate clockwise
The corner between the screen and the display surface (101a) comes into contact with the inclined surface (721) of the central protruding portion (72) of the support (7), and the rotation of the display element (10) stops (the state of FIG. 10). ). In this state, when the current supply to the second electromagnet (61) is stopped and the support (7) is further lowered, the display element () is brought into contact with the side projection (71) until the display surface (101d) abuts. When 10) rotates clockwise and the support (7) passes, the display element (10) is rotated exactly 90 ° from the state of FIG. 9 and the display surface (101b) is displayed (state of FIG. 11). Stop at To display the display surface (101d), FIG.
, The display surface (101b) is displayed, except that the display element (10) side of the second electromagnet (61) is set to be the S-pole so as to approach the display element (10). Do the same.

As described above, the four display surfaces of the display element can be freely displayed, and an image (or a part of the image) formed from the displayed display surface can be changed at a desired time. For example, in a display having only one display element, an independent image is drawn on each display surface of the display element, and four images can be displayed at desired times.

Further, the display device has a plurality of display elements arranged in parallel in a predetermined arrangement, and each display surface of each display element forms a part of an image, and an aggregate of display surfaces of each element displayed simultaneously is One image can be formed. In this case as well, basically four types of images are displayed, but it is also possible to form more images by freely combining the four display surfaces. The plurality of display elements can be arranged vertically (with respect to the installation surface of the display body) or horizontally. Further, as shown in FIG.
A plurality of display elements can be arranged in a matrix. Such an arrangement is preferable because a plurality of images can be freely displayed.

Preferably, each display element is substantially cubic. That is, as shown in the drawings, each display element has four display surfaces colored in four different colors, and each display element can display each display surface independently. In this way, the aggregate of each display surface can form one image, and these display surfaces can be effectively combined to display four or more images (including designs and characters).

In the display having a plurality of display elements arranged in a matrix as described above, the built-in magnet (5) arranged inside the display element and the display capable of acting on the built-in magnet (5) as described above. It is preferable that the display element is rotated by utilizing attraction and repulsion of the display element with the rotating magnets (60, 61) movably arranged at a position outside the element. In such a case, a gap (for example, 1 mm to 3 cm) between the display elements adjacent to each other is dimensioned so as not to hinder the rotation of each other.
Is preferably provided.

A variable display device including a plurality of display elements arranged in a matrix is disclosed in the above-mentioned Japanese Patent Application Laid-Open Nos. 57-60370 and 57-60371. Further, in the display body including the `` a plurality of display elements arranged in a matrix '' as described above, openings are provided on both the front surface of the housing and the rear surface facing the housing, and the design and the like are the same from both front and rear directions. Two types of images having different color combinations can be made observable.

In the above description, the number of display surfaces of the display element is four.
However, the number of display surfaces may be two or more, and is not particularly limited. For example, (i) a plate-like element having two main surfaces as display surfaces, and (ii) a display element having a substantially triangular prism and having three display surfaces can be used in the same manner as described above.
In the case of a plate-like element, a display having a structure like a louver type blind can be formed, and two different images can be formed from the front and back display surfaces of the plate-like element.

Further, a display element having five or more display surfaces can be used. For example, as shown in FIGS. 12 and 13, a display member (122) in which five strip-shaped plate members (121) are connected in a ring shape is composed of two triangular prisms arranged at a predetermined distance from each other. Rotating member (123, 12
4) A display element (120) arranged around can be used. The display member (122) is flexibly connected between the plate members (121) adjacent to each other, and has five support pins (12) abutting on the inner peripheral sides of the five connection portions.
5) are arranged in a predetermined spaced arrangement. The outer surface (128) of each plate member (121) is a display surface on which the retroreflective film is disposed. That is, one display element can display five types of images or a part of the images.

The rotating members (123, 124) are respectively rotatable around rotation axes (126, 127). The rotating members (123, 124) rotate in synchronization with each other,
In accordance with the rotation, the display member (122) is rotated by the rotation member (1).
23, 124), and the observed display surface is 5
Change to kind. For example, at least one of the rotating members is fixedly connected to a rotating shaft, and the rotating shaft can be directly connected to the driving device to rotate the rotating shaft. Even when such a display element is used, similarly to the case of the above-described substantially rectangular parallelepiped display element, a plurality of display elements can be arranged in a line in a vertical or vertical direction or arranged in a matrix. it can.

As described above, the display surface observed by the rotation of the display element changes, and the image formed by the display surface changes. In addition, the display surfaces of all display elements
An external illuminator in which a retroreflective film having the above-mentioned characteristic (A) is arranged and which illuminates an image surface composed of a display surface of a display element is usually illuminated with illumination light from the entire surface of the image surface. Angle (θ) is 0 ° -9
It is arranged so that it is incident at less than 0 °. Therefore, the image can be observed while changing, the appearance in both day and night can be made almost the same, and the visibility and legibility can be enhanced.
The area of the entire image surface of the display of the present invention can be appropriately determined depending on the application. For example, when used as a sign or advertisement viewed from a relatively far distance, it is usually 1 to 50 m ²
Range.

Retroreflective Film The retroreflective film used in the present invention has an observation angle characteristic (A), that is, a reflection luminance of 0.degree. When the incident angle is 0 ° and the observation angle is in the range of 10 ° to 20 °. 2-100 cd
・ Lux ^-1・ m ^-2 The reflection luminance is JIS Z
Measured according to 9117. 0.2cd
If it is less than lux ^-1 · m ^-2 , the visibility of the image at night is reduced, while if it exceeds 100 cd · lux ^-1 · m ^-2 , the legibility of information such as characters contained in the image is reduced. In addition, there is a great possibility that the appearance in day and night, that is, the appearance under daylight is different from the appearance under night illumination. The reflection luminance at an incident angle of 0 ° and an observation angle of less than 10 ° (for example, 4 °) is usually 0.2 cd · lux.
⁻¹ · m ⁻² or more, preferably 1 or more, particularly preferably 10 to 5
It is in the range of 00 cd · lux ⁻¹ · m ⁻² . The illuminance on the image plane (plate illuminance) is usually 10 to 400 lux.
And using an external lighting device. In addition, some of less than one or all of the plurality of display surfaces,
When an image is formed using a coloring material having relatively low light transmittance, the upper limit of the observation angle characteristic (A) is 100 cd · lu.
Use a retroreflective sheet exceeding x ^-1 · m ^-2 and use only the other display surface (display surface colored with a colorant with relatively high light transmittance or white display surface without coloring) It is preferable to use a retroreflective sheeting having the observation angle characteristic (A). Also, depending on the type and installation conditions of the projector,
The plate surface illuminance is not particularly limited to the above range.

Here, the term "retroreflective film" refers to a retroreflective sheet as described later, a plurality of transparent bead lenses, a binder for fixing the same, and a paint containing a specular reflective material. And a coating-type retroreflective film formed by coating on a side surface of a display element. Examples of the specular reflection material include metal powder, guanine obtained from fish scales, and pearlescent pigments. As the binder, polymers used in ordinary coatings, for example, acrylic polymers, polyurethanes, vinyl chloride polymers and the like can be used.

In a preferred embodiment of the present invention, as a part of the reflecting component (ie, a plurality of microlenses), the refractive index is measured using a sodium D line at 20 ° C. and 50% RH using a polarizing microscope. The display surface is formed by using a capsule lens type retroreflective sheet containing two types of beads having different values. Capsule lens type retroreflective sheeting
Usually, as shown in FIG. 14, a layer (40) of a plurality of spherical microlenses (glass beads) (41) and a light-transmitting coating film disposed at a predetermined distance from the lens layer (40) (42), a bonding layer (43) that supports the plurality of microlenses (41) in a partially buried state and is partially bonded to the light-transmitting coating film (42), and is buried in the bonding layer (43). And a reflection film (44) for covering the portion of the lens (41).

An adhesive layer (45) is usually arranged on the back surface (the surface opposite to the lens layer) of the bonding layer (43), and is fixed to the display element via the adhesive layer (45). The adhesive surface of the adhesive layer (45) is usually liner (4) until it is fixed.
It is protected in step 6), and is removed when the work of fixing to the display element is performed. The basic structure and manufacturing method of such a retroreflective sheet are disclosed in Japanese Patent Publication No. 40-7870,
It is disclosed in Japanese Patent Publication No. 61-13561 and the like.

One characteristic of the retroreflective sheet used in one preferred embodiment of the present invention is that the beads have a size of 1.5 to 1.5.
A first bead having a refractive index in the range of 2.0;
This is a point consisting of the second beads having a refractive index at least 0.1 larger than the refractive index of the beads. By using two kinds of beads having such a refractive index characteristic, a retroreflective sheet having the above-mentioned observation angle characteristic (A) can be easily provided, and the display surface of the variable image display has high brightness and high white color. And a wide observation angle (being able to be visually recognized well in a predetermined observation angle range by external illumination at night) can be effectively provided. Such a variable image display is well visible at night, even from motor vehicle and truck drivers, with external lighting and looks nearly identical both day and night.

If the refractive index of the first and second beads is less than 1.5, the crystallization of the bead-forming material such as glass may proceed to cause devitrification. A larger difference in the refractive index between the two types of beads is advantageous in enhancing the wide observation angle at night, further increasing the whiteness of the retroreflective sheet, and enhancing the design in daytime. However, when the refractive index of the first beads exceeds 2.0, it may be difficult to increase the difference between the refractive index of the first beads and that of the second beads. This is because even when the refractive index of the beads greatly exceeds 2.0 (for example, 2.3 or more), the beads are liable to devitrify.

On the other hand, if the difference between the refractive indices of the two types of beads is too large, the reflection luminance is reduced when the incident angle is 0 ° and the observation angle is in the range of 10 ° to 20 °. May be present. If the difference in the refractive index is too small, the whiteness may be reduced. Therefore, 2
The difference in the refractive index between the types of beads is usually in the range of 0.1 to 0.8, preferably 0.2 to 0.7, particularly preferably 0.4 to 0.6. Further, the second beads preferably have a refractive index of 1.9 to 2.1. Thereby, the luminance of the retroreflective sheet can be effectively increased.

The volume ratio of the first beads to the second beads (first
The ratio of bead to second bead) is arbitrary as long as the above-mentioned effect can be obtained. However, usually 10: 90-9
0:10, preferably 30:70 to 70:30, particularly preferably 40:60 to 60:40. If there are too many other beads relative to one bead, the observation angle cannot be widened. That is, it is advantageous that the difference between the amount of one bead and the amount of the other bead is smaller.

As a material for the beads, for example, a transparent inorganic material such as glass, ceramic, and glass-ceramic can be used. The average particle size of each bead is 30 to 850 as a value measured by an image processing device through a microscope.
μm is preferred. If the thickness is less than 30 μm, light may be scattered and sufficient brightness may not be obtained. Could be From such a viewpoint, a suitable average particle size is in the range of 35 to 200 μm.

The capsule lens type retroreflective sheet can be manufactured by a conventionally known method disclosed in the above-mentioned publications. For example, it can be manufactured by a method including the following steps (1) to (7). (1) Glass beads are partially removably embedded in a polyethylene coat layer on a carrier web to form a glass bead layer made of glass beads. (2) On the surface of the exposed glass beads of the glass bead layer,
A reflection film is provided by a thin film forming means. (3) The bonding layer and the release film are laminated on the reflection film. (4) After the above (3), the carrier web is removed to expose the surface of the glass bead supported by the binding layer on which the reflection film is not provided. (5) The covering film is disposed at a predetermined spatial distance from the surface of the glass bead where the reflective film is not provided. (6) The embossing die having the mesh-shaped narrow line is pressed from above on the release film while being heated, whereby the bonding layer is embossed through the release film, and the bonding layer and the coating film are partially formed. Form a small-meshed connecting part (consisting of a part of the bonding layer) which is adhered. (7) The release film is removed, the surface of the bonding layer opposite to the side to which the coating film is bonded is exposed, and an adhesive layer provided with a liner is laminated on the surface.

The adhesive layer can be formed from, for example, an acrylic adhesive, a silicone adhesive, a polyurethane adhesive, an epoxy adhesive, or the like. Further, it is preferable to use a pressure-sensitive adhesive as an adhesive, since the work of sticking (sticking) to the display element becomes easy. When the display is used outdoors, the adhesive is required to have heat resistance and weather resistance. Therefore, it is preferable that the adhesive contains a crosslinking agent.

The retroreflective sheet used in the present invention is:
It is not limited to the above as long as the observation angle characteristic (A) is satisfied. For example, a capsule lens type retroreflective sheet using three or more types of glass beads having different refractive indices can also be used. Also, an exposed lens type or encapsulated lens type retroreflective sheet using two or more types of glass beads having different refractive indices can be used. Furthermore, a prism type retroreflective sheeting in which the dimensions, shape, arrangement, and the like of the cube corner prism are designed so as to satisfy the observation angle characteristic (A) can also be used.

The display surface of the display element is formed, for example, by attaching a retroreflective film via an adhesive to a predetermined side surface of the display element body having a substantially rectangular parallelepiped shape. At this time, each display surface is colored in a different color (usually four colors), or a retroreflective film in which different characters or designs are drawn is used. For the formation of coloring, characters, and the like, a light-transmitting ink, such as a toner for an electrostatic printer or an ink-jet ink, is usually used. For example, in the case of a capsule lens type retroreflective sheet, a coloring layer or a printing layer is provided on the front surface or the back surface (the surface bonded to the bonding layer) of the light-transmitting coating film by using application means such as coating and printing. Do. In addition, the coating film may contain ink to form a colored light transmissive film. The light-transmitting ink is composed of, for example, a mixture of an azo-based, perylene-based, phthalocyanine-based pigment or the like, and an acrylic-based, vinyl chloride-based, urethane-based resin, or the like.

The total light transmittance (according to JISK 7105) of the coated film on which the colored or character or the like is formed is usually 8% or more, preferably 10% or more in the case of blue, and usually 10% or more in the case of red. 25% or more, preferably 30% or more,
In the case of green, it is usually at least 10%, preferably at least 15%. In the case of a transparent coated film, the total light transmittance is usually 80% or more, preferably 85% or more. Toners for electrostatic printers, inks for inkjet, etc. can be printed directly on the coating film of a retroreflective sheet,
An image may be formed on a transparent receptor film with an adhesive, which may be used by attaching it to a retroreflective sheet.

Variable Image Display System FIG. 15 is a diagram showing one mode of use of a variable image display system including a road sign composed of the above-mentioned display and an external lighting device. In the figure, T1 and T2 are traveling lanes 1 and 2, S1 is a side road, and E is a road shoulder. Reference numeral 1 denotes a road sign (a variable image display having a road sign as an image), and reference numeral 2 denotes an external lighting device disposed on a road shoulder. The illuminating device 2 includes a column 20b and a projector 20a attached to an upper end of the column 20b. X is the height from the road surface to the lower end of the road sign, Y is the height of the road sign itself, W is the width of the road sign, L is the horizontal distance between the external lighting device 2 and the road sign 1, and H is the external lighting device. The height of 20 posts.

The irradiation light from the light projector 20a to the road sign 1 is indicated by a dotted line, and the irradiation angles θ at the vertices A, B, C, and D of the road sign 1 are indicated by θ ₁ , θ ₂ , θ _3, and θ ₄ , respectively.
And However, it is assumed that the road sign 1 is disposed at right angles to the traveling lanes T1 and T2. The irradiation angle is
It refers to the angle formed between the irradiation light beam and the normal to the marker surface at a point (vertex) on the marker surface (image surface).

The external lighting device 2 includes, for example, a road sign 1
Irradiation angle theta _i from the external illuminating device 2 with respect to the, i = 1
For all of ~ 4

## EQU1 ## The arrangement is such that 0 ° <θ _i <30 ° is satisfied. At this time, the external lighting device 2
Is defined as follows. FIG. 16 is a diagram for explaining the regulation of the column height H. When the vehicle 4 is located 200 m before the road sign 1, in a preferred embodiment of the present invention, the column height H is determined by the following relational expression:

## EQU2 ## (100-L) X / 100 <H <(X + Y) (30
0−L) / 300 is preferably satisfied. This allows
Night visibility and legibility are effectively enhanced. here,
The distance 200 m to the vehicle is the optimal visual distance as seen from the driver. With this distance, the elevation angle at which the driver looks at the road sign approaches substantially “0 °”, and the visibility and the like are effectively improved.

The external illuminating device used in the variable image display system of the present invention has a predetermined illumination condition (irradiation angle θ).
Etc.) are not particularly limited as long as they can satisfy the above conditions. For example, an apparatus having a light projector such as a spotlight or a searchlight can be used.

FIG. 17 is an exploded view of a main part of a preferred projector. 71 is a lamp, 72 is a reflector, 73 is a limiter, and 74 is a Fresnel lens. When an illumination device (projector) is installed separately from the display body, for example, on the road shoulder (for example, 20a in FIG. 15), it is necessary to give sufficient consideration to light leakage to the rear of the display body. Light off the display, for example, if the display is a road sign, can affect the driver of a car traveling in the oncoming lane and can cause traffic obstruction. Therefore, it is preferable that the light projector limits the irradiation area to the image surface of the sign.

In the configuration of the main part of the projector shown in FIG. 17, an external scene is shown on the surface of the limiter 73 placed at the focal point of the Fresnel lens 74. Except, mask the other parts with tape. That is, the tape is stuck so as not to be reflected. Thus, it is possible to limit the irradiation light from the lamp 71 to irradiate the image surface. As shown in FIG. 4, an external illumination device 2 including two or more projectors 20a can be used.

[0051]

Embodiment (Embodiment 1) Retroreflective Sheet A capsule lens type retroreflective sheet as shown in FIG. 14 was produced. The microlens has a refractive index of 1.65 and 5
It was made of glass beads in which 0% and a refractive index of 1.5 were uniformly mixed at a volume ratio of 50%, and an aluminum vapor-deposited film was used as a reflective film. The color of the retroreflective film under daylight (observed with the naked eye) was white. Also, JIS Z
The reflection luminance measured by the method according to 9117 is
When the incident angle was 0 ° and the observation angle was in the range of 10 ° to 20 °, it was in the range of ^{1 to} 1.5 cd · lux ⁻¹ · m ⁻² .

2. Variable information display 1. Using the retroreflective film produced in the above, a plurality of display elements arranged in a matrix as shown in FIG.
(15 widths) were manufactured. Each display element was formed of a cube having a side of about 16 cm, and the above-mentioned retroreflective film was adhered to four surfaces other than the side surface having a rotation axis via an acrylic pressure-sensitive adhesive layer to form four display surfaces. Three of these four surfaces were colored red, blue, and green, respectively, using light-transmitting ink for a road sign reflection sheet, and the other surface was left white. The dimensions of the housing were about 3 m in width and about 2 m in length.

Using the display body manufactured as described above, the display body and the external lighting device were arranged in a positional relationship as shown in FIG. 15, and the visibility and legibility of the image both day and night were confirmed. . Visibility and legibility are good day and night,
The appearance in both day and night was almost the same in all four colors (including white).

(Example 2) Glass beads obtained by uniformly mixing a capsule lens type retroreflective film with a volume ratio of 50% with a refractive index of 1.93 and 50% with a refractive index of 1.5 are used. A variable image display of this example was formed in the same manner as in Example 1 except that the variable image display was formed. The color of the retroreflective film used in this example under daylight was white. The reflection luminance measured by a method based on JISZ 9117 is such that the incident angle is 0 ° and the observation angle is 10 ° to 2 °.
0.8 to 1.2 cd · lux ^-1 · m ^{-2 in} the range of 0 °
Was in the range.

Using the display of this example, the display and the external lighting device were arranged in a positional relationship as shown in FIG. 15, and the visibility and legibility of the image both day and night were confirmed. The visibility and legibility were good both day and night, and the appearance both day and night was almost the same for all four colors.

[Brief description of the drawings]

FIG. 1 is a perspective view of one embodiment of a display element used in the present invention.

FIG. 2 is a cross-sectional view of one embodiment of the variable image display of the present invention.

FIG. 3 is an enlarged sectional view of a rotating shaft and a through hole of the display element of FIG. 1;

FIG. 4 is a perspective view of another embodiment of the variable image display of the present invention.

FIG. 5 is a perspective view of another embodiment of the display element used in the present invention.

FIG. 6 is a cross-sectional view of the display element of FIG.

FIG. 7 is a diagram showing a first step of a method of driving the display element of FIG.

FIG. 8 is a view showing a second step of the method for driving the display element of FIG. 4;

FIG. 9 is a view showing a third step of the method for driving the display element of FIG. 4;

FIG. 10 is a view showing a fourth step of the method for driving the display element of FIG. 4;

FIG. 11 is a view showing a fifth step of the method for driving the display element of FIG. 4;

FIG. 12 is a plan view of still another mode of the display element used in the present invention.

FIG. 13 is a perspective view of the display element of FIG.

FIG. 14 is a sectional view of an example of a retroreflective film used in the present invention.

FIG. 15 is a schematic diagram of a variable image display system using the variable image display of the present invention as a road sign.

FIG. 16 is a view for explaining a method of defining a column height H of the external lighting device of FIG.

FIG. 17 is an exploded perspective view of a main part of a light projector preferably used with the variable image display of the present invention.

[Explanation of symbols]

10: display element, 11: housing, 12: rotation axis, 1
3: Through hole, 14: Image surface 5: Magnet, 60, 61: Electromagnet, 7: Support base 40: Microlens layer, 41: Lens, 42: Light transmissive coating film, 43: Coupling layer, 44: Reflection film , 45: adhesive layer, 46: liner 101a, 101b, 101c, 101d: display surface, 1
02, 103: side surface 121: plate member, 122: display member, 123, 124:
Rotating member, 125: support pin, 126, 127: rotating shaft, 128: outer surface

Claims (2)

[Claims] 1. a) a plurality of display surfaces (101a to 101);
a display element (10) having d), wherein the display surface that is visible when the display surface is visible from the outside constitutes at least a part of the image surface (14); and b) the display element (10). And a housing (11) for movably storing the display image. The display element (10) is capable of holding at least one of the plurality of display surfaces from the outside and capable of holding a display state. In the display (1), at least one of the display surfaces (101a to 101d) is formed of a retroreflective film having an observation angle characteristic (A) defined below, and is a variable image. Display: Observation angle characteristics (A): The reflection luminance measured by a method in accordance with JIS Z 9117 is 0.2 to 100 cd · at an incident angle of 0 ° and an observation angle of 10 to 20 °.
lux ^-1 · m ^-2 2. The retroreflective film comprises a capsule lens-type reflective sheet including a plurality of beads as microlenses, wherein the plurality of beads have a refractive index in a range of 1.5 to 2.0. A first bead and a second bead having a refractive index at least 0.1 greater than a refractive index of the first bead, wherein a volume ratio of the first bead to the second bead is 10:90.
The variable image display according to claim 1, wherein the range is from 90 to 10:10.