CROSS REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Phase Application under 35 U.S.C. 371 of International Application No. PCT/JP2017/014901 filed on Apr. 12, 2017. This application is based on and claims the benefit of priority from Japanese Patent Applications No. 2016-104630 filed on May 25, 2016 and No. 2017-028147 filed on Feb. 17, 2017. The entire disclosures of all of the above applications are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a head-up display device (hereinafter abbreviated to HUD device) configured to be mounted on a movable object and to display a virtual image to be visually recognized by an occupant.

BACKGROUND ART

Conventionally, an HUD device, which is mounted on a movable object and displays a virtual image to be visually recognizable by an occupant, has been known. The HUD device disclosed in Patent Literature 1 includes a light emitting device array and an image formation unit. In the light emitting device array, multiple light emitting devices that emit illumination light are arrayed in a device array direction. The image formation unit forms an image according to illumination of an illumination light and emits the formed image as a display light.

In addition, the HUD device includes two lens arrays that are arrayed according to the device array direction and condense the illumination light. An array pitch of the light emitting devices is set to be smaller than an array pitch of lens surfaces in the two lens arrays. The light emitting devices and apexes of lens surfaces corresponding to the light emitting devices are arranged on a straight line. In other words, attempt is made to reduce luminance unevenness of a virtual image when an occupant moves his head by using eccentricity toward a center side of the light emitting devices with respect to the two lens arrays.

However, due to the eccentricity of the multiple light emitting devices to the center side, a light quantity of the display light reflected by a projection member is concentrated in a narrow range, and the display light does not reach a wide range. As a result, for example, when the occupant moves his head more greatly, the luminance of the virtual image sharply decreases. For that reason, there is room for improvement in the visibility of the virtual image.

PRIOR TECHNICAL LITERATURE

Patent Literature

PATENT LITERATURE 1: JP 2015-232943 A

SUMMARY OF INVENTION

The present disclosure aims at providing an HUD device with high visibility of a virtual image.

According to one aspect of the present disclosure, a head-up display device is configured to be mounted on a movable object. The head-up display device is configured to project a display light of an image on a projection member and to cause the projection member to reflect the display light to display a virtual image of the image to be visually recognizable by an occupant. The head-up display device comprises a light emitting device array including a plurality of light emitting devices configured to emit illumination light and arrayed in a plurality of device array directions. The head-up display device further comprises an image formation unit configured to form the image according to illumination caused by the illumination light and to emit the image as the display light. The head-up display device further comprises an optical member including a diverging unit, which is located in an optical path between the light emitting device array and the image formation unit, and configured to exert a diverging action in at least one specific direction among the plurality of device array directions on the illumination light from the respective light emitting devices. The diverging unit includes one or more refractive surfaces configured to refract the illumination light while exerting the diverging action.

According to one aspect of the present disclosure, a head-up display device is configured to be mounted on a movable object. The head-up display device is configured to project a display light of an image on a projection member and to cause the projection member to reflect the display light to display a virtual image of the image to be visually recognizable by an occupant. The head-up display device comprises a light emitting device array including a plurality of light emitting devices configured to emit illumination light and arrayed in a device array direction. The head-up display device further comprises an image formation unit configured to form the image according to illumination caused by the illumination light and to emit the image as the display light. The head-up display device further comprises an optical member including a diverging unit, which is located in an optical path between the light emitting device array and the image formation unit, and configured to exert a diverging action in the device array direction on the illumination light from the respective light emitting devices. The diverging unit includes one or more refractive surfaces configured to refract the illumination light. The one or more refractive surfaces have one main axis in a cross section including the device array direction.

According to one aspect of the present disclosure, an image projection unit is for a head-up display device configured to be mounted on a movable object. The head-up display device is configured to project a display light of an image on a projection member and to cause the projection member to reflect the display light to display a virtual image of the image to be visually recognizable by an occupant. The image projection unit comprises a light emitting device array including a plurality of light emitting devices configured to emit illumination light and arrayed in a plurality of device array directions. The image projection unit further comprises an image formation unit configured to form the image according to illumination caused by the illumination light and to emit the image as the display light. The image projection unit further comprises an optical member including a diverging unit located in an optical path between the light emitting device array and the image formation unit and configured to exert a diverging action in at least one specific direction among the plurality of device array directions on the illumination light from the respective light emitting devices. The diverging unit includes one or more refractive surfaces configured to refract the illumination light while exerting the diverging action.

According to one aspect of the present disclosure, an image projection unit is for a head-up display device configured to be mounted on a movable object. The head-up display device is configured to project a display light of an image on a projection member and to cause the projection member to reflect the display light to display a virtual image of the image to be visually recognizable by an occupant. The image projection unit comprises a light emitting device array including a plurality of light emitting devices configured to emit illumination light and arrayed in a device array direction. The image projection unit further comprises an image formation unit configured to form the image according to illumination caused by the illumination light and to emit the image as the display light. The image projection unit further comprises an optical member including a diverging unit located in an optical path between the light emitting device array and the image formation unit and configured to exert a diverging action in the device array direction on the illumination light from the respective light emitting devices. The diverging unit includes one or more refractive surfaces configured to refract the illumination light.

