CROSS-REFERENCE TO RELATED APPLICATION

This patent application is based upon and claims the benefit of priority under 35 USC 119 from Japanese Patent Application No. 2019-074718 filed on Apr. 10, 2019, the entire disclosure of which, including the specification, claims, drawings, and abstract thereof, is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a projector, a projection control device, and a storage medium.

Description of the Related Art

Conventionally, there has been disclosed a projector in which a light source unit including light emitting devices configured to emit colors of light are driven in time division. For instance, in a projector disclosed in Japanese Patent Laid-Open No. 2012-155268, a spoke period is set as a time period during which colors of light from a light source unit are switched over. In the spoke period, colors of light are mixed up. Setting components of colors of light in the spoke period in advance can set a color mode in which the brightness of an image is enhanced or the chromaticity of the image is enhanced.

In colors of light that are mixed up in the spoke period, however, the light emitting amount of each light emitting device may vary, for example, as a result of the driving current of the light emitting device varying depending upon a color mode to be used. This may cause a discontinuous gradation in a gradational image.

SUMMARY OF THE INVENTION

The present invention has been made in view of the situations described above, and an object of the present invention is to provide a projector, a projection control device, and a storage medium that can hold gradation repeatability.

According to an aspect of the present invention, there is provided a projector including: a light source unit including a semiconductor light emitting element and a color wheel and configured to emit a plurality of colors of light including light in a first wavelength range and light in a second wavelength range in time division; a display device on to which light source light is shined from the light source unit to form image light; a projection optical system configured to project the image light emitted from the display device on to a projection target; a delay time setting module configured to shift a start timing of a color mixing period when the light in the first wavelength range and the light in the second wavelength range are emitted in a mixed fashion in a spoke period of the color wheel which constitutes a period when an emission of the light in the first wavelength range and an emission of the light in the second wavelength range are switched over based on an index indicating a brightness of light emitted from the light source unit; and a light source driving module configured to drive the light source unit based on a setting set by the delay time setting module.

According to another aspect of the present invention, there is provided a projection control device comprising: a delay time setting module configured to shift a start timing of a color mixing period when light in a first wavelength range and light in a second wavelength range are emitted in a mixed fashion in a spoke period of a color wheel which constitutes a period when an emission of the light in the first wavelength range and an emission of the light in the second wavelength range are switched over based on an index indicating a brightness of light emitted from a light source unit comprising a semiconductor light emitting element and the color wheel and configured to emit a plurality of colors of light including the light in the first wavelength range and the light in the second wavelength range in time division; and a light source driving module configured to drive the light source unit based on a setting set by the delay time setting module.

According to a further aspect of the present invention, there is provided a storage medium that a computer can read, the storage medium being configured to cause the computer to function as: a delay time setting module configured to shift a start timing of a color mixing period when light in a first wavelength range and light in a second wavelength range are emitted in a mixed fashion in a spoke period of a color wheel which constitutes a period when an emission of the light in the first wavelength range and an emission of the light in the second wavelength range are switched over based on an index indicating a brightness of light emitted from a light source unit comprising a semiconductor light emitting element and the color wheel and configured to emit a plurality of colors of light including the light in the first wavelength range and the light in the second wavelength range in time division; and a light source driving module configured to drive the light source unit based on a setting set by the delay time setting module.

