FIELD

The present invention relates to a display device for displaying multiple patterns and an exhibition apparatus including the display device.

BACKGROUND

Vending machines for commonly selling multiple types of products are expected to display, for example, descriptions or advertisements corresponding to the products. A known switching display device in a vending machine includes display units provided for different products selectable in the vending machine. Each display unit includes a display member including two backlight displays arranged in parallel in a predetermined direction, front and back translucent flat light guide plates extending, behind the display member, parallel to each other from one end of the displays to the other end of the corresponding display in the predetermined direction and each including a light diffusion part in an area behind the corresponding display, and light emitters each facing an end face of the corresponding light guide plate in the predetermined direction in a selectively drivable manner (refer to, for example, Patent Literature 1).

CITATION LIST

Patent Literature

Patent Literature 1: Japanese Unexamined Patent Application Publication No. 2007-183853

SUMMARY

Technical Problem

Although the switching display device described in Patent Literature 1 selectively turns on the light emitters to switch its display, the display corresponding to the on-state light emitters will appear, irrespective of the direction in which the switching display device is viewed. In some situations, however, the display is to be switched depending on the viewing direction.

One or more aspects of the present invention are directed to a display device that can switch display patterns depending on the viewing direction.

Solution to Problem

One aspect of the present invention provides a display device. The display device includes a transparent light guide plate having an incident surface to display a plurality of patterns viewable in different directions, and at least one light source facing a part of the incident surface. The light guide plate includes, on a first surface of the light guide plate, a plurality of prisms arranged along each of the plurality of patterns. The plurality of prisms have, for each pattern, reflection surfaces that reflect light emitted from the at least one light source and entering the light guide plate through the incident surface in a direction in which the pattern is viewable.

The display device with the above structure can switch display patterns depending on the viewing direction.

In the display device, each of the patterns may be viewable in a different direction with respect to a direction orthogonal to the incident surface of the light guide plate, and each of the patterns may have an angle between the reflection surface of each of the plurality of prisms forming the pattern and the first surface of the light guide plate that is set in accordance with the direction in which the pattern is viewable.

The display device can thus switch display patterns depending on the viewing direction although each pattern is viewable in a different direction with respect to the direction orthogonal to the incident surface of the light guide plate.

In the display device, each of the patterns may be viewable in a different direction with respect to a direction parallel to the incident surface of the light guide plate, and each of the patterns may have an angle between a direction in which the reflection surface of each of the plurality of prisms forming the pattern directly faces and a direction from the reflection surface toward the at least one light source that is set in accordance with the direction in which the pattern is viewable.

The display device can thus switch display patterns depending on the viewing direction although each pattern is viewable in a different direction with respect to the direction parallel to the incident surface of the light guide plate.

In the display device, the at least one light source may include a plurality of light sources arranged in a longitudinal direction of the incident surface, and the plurality of prisms may be arranged to allow, for each pattern, the reflection surface of each of the plurality of prisms forming the pattern to reflect light emitted from a corresponding light source among the plurality of light sources and entering the light guide plate through the incident surface in a direction in which the pattern is viewable.

The display device includes the light source for each pattern, and thus increases the brightness of the display pattern to improve the viewability of the patterns.

The display device may further include a control circuit that turns on, in accordance with a control signal specifying a display pattern from the plurality of patterns, a light source corresponding to the pattern specified by the control signal among the plurality of light sources.

The display device can thus display an intended pattern selectively from the multiple patterns.

Another aspect of the present invention provides an exhibition apparatus. The exhibition apparatus includes a mount on which an exhibition target is mountable, and a display device located in front of the exhibition target. The display device includes a transparent light guide plate having an incident surface and a first surface facing the exhibition target to display a plurality of patterns viewable in different directions, and at least one light source facing a part of the incident surface. The light guide plate includes, on the first surface of the light guide plate, a plurality of prisms arranged along each of the plurality of patterns. The plurality of prisms have, for each pattern, reflection surfaces that reflect light emitted from the at least one light source and entering the light guide plate through the incident surface in a direction in which the pattern is viewable.

The exhibition apparatus with the above structure can switch patterns to be displayed together with the exhibition target depending on the viewing direction.

