Distance measuring apparatus
AssigneeCanon Kabushiki Kaisha
InventorsMinoru Takasaki, Yukihiro Matsumoto
Life of this patent
Estimating the term…
Abstract
In a distance measuring apparatus for measuring the distance to an object on the basis of reflected light obtained as a result of projecting light toward the object, in the case of an active distance measurement operation, the flickering frequency of a light beam projected from a light projection unit (B) toward the object (A) is prolonged within the range in which charges obtained by a signal charge supply unit (C) are not saturated in a circulating shift register (E). When the flickering period is longer than a predetermined period, a distance measurement operation inhibition unit (L) inhibits transition to a passive distance measurement operation.
Claims27
A distance measuring apparatus, which comprises light projection means driven to flicker and project light beam pulses onto an object, and distance measuring means for measuring a distance to the object on the basis of reflected light obtained by projecting the light beam pulses onto the object, comprising:
- detection means for detecting a situation of the object;
- flickering frequency changing means for changing a flickering frequency of said light projection means in accordance with the situation of the object detected by said detection means;
- and
- photoelectric conversion means, signal charge integral means, signal charge supply means, signal charge injection means, and a circulating shift register,
- wherein said photoelectric conversion means comprises a plurality of photoelectric conversion elements for photoelectrically converting the light beam pulses consequently obtained when the light beam pulses projected from said light projection means are reflected by the object, and outputting signal charges,
- said signal charge integral means integrating the signal charges respectively output from said plurality of photoelectric conversion elements,
- said signal charge supply means transferring the signal charge integrated by said signal charge integral means to said signal charge injection means in accordance with a predetermined pulse,
- said signal charge injection means injecting the signal charge transferred by said signal charge supply means into said circulating shift register,
- said circulating shaft register accumulating the signal charge injected from said signal charge injection means, and
- said distance measuring means calculates the distance to the object on the basis of the signal charge accumulated in said circulating shift register.
A distance measuring apparatus, which comprises light projection means driven to flicker and project light beam pulses onto an object, and distance measuring means for measuring a distance to the object on the basis of reflected light obtained by projecting the light beam pulses onto the object, comprising:
- detection means for detecting a situation of the object;
- and
- flickering frequency changing means for changing a flickering frequency of said light projection means in accordance with the situation of the object detected by said detection means,
- wherein said distance measuring means can operate in one of an active mode for measuring distance by driving said light projection means to emit light, and a passive mode for measuring distance without driving said light projection means to emit light, and
- said apparatus further comprises inhibition means for, when the flickering period of said light projection means is longer than a predetermined period, inhibiting transition to the passive mode.
A distance measuring apparatus, which comprises light projection means driven to flicker and project light beam pulses onto an object, and distance measuring means for measuring a distance to the object on the basis of reflected light obtained by projecting the light beam pulses onto the object, comprising:
- detection means for detecting a situation of the object;
- flickering frequency changing means for changing a flickering frequency of said light projection means in accordance with the situation of the object detected by said detection means;
- continuous operation setting means for continuously operating said distance measuring means;
- and
- flickering frequency limiting means for, when said continuous operation setting means sets to continuously operate said distance measuring means, inhibiting a flickering frequency of said light projection means from being set to be lower than a predetermined value.
Dependencies are inferred from the claim text.