Distance measuring apparatus using passive AF sensor
A distance measurement object is imaged by a pair of line sensors of an AF sensor, and sensor data showing the sensor images is generated. A CPU generates AF data showing the contrast of sensor images with the sensor data being sequentially acquired by the CPU for each cell. Then, the AF data is used to carry out calculation of correlation values or the like, thereby calculating the distance from the distance measurement object. Thus, generation of AF data for distance measurement calculation such as correlation value calculation showing the contrast of the sensor images formed by the pair of line sensors of the AF sensor, and distance measurement calculation using the AF data are carried out by the computation processing circuit (CPU) to simplify the circuit, and also the sensor data is sequentially acquired from the AF sensor, and at the same time the AF data is sequentially generated, whereby the amount of processing time for generation of the AF data is significantly reduced to shorten distance measurement time.
1. A distance measuring apparatus, comprising:
an AF sensor which forms images of light from a distance measurement object on a pair of line sensors comprising a plurality of light receiving elements and integrates signals obtained from the light receiving elements for each of the plurality of light receiving elements to generate a pair of sensor data; and
a computation processing circuit which acquires the pair of sensor data generated by the AF sensor from the AF sensor, generates a pair of AF data for distance measurement calculation showing contrast of sensor images formed by the pair of line sensors by difference calculation processing according to the pair of sensor data, and calculates a distance from the distance measurement object according to the AF data, where the pair of the AF data is generated before the computation processing circuit acquires another pair of sensor data generated by the AF sensor from the AF sensor for generating another pair of AF data for the distance measurement calculation,
wherein the computation processing circuit generates the AF data and stores the generated AF data in a memory before starting the distance measurement calculation, and uses the AF data stored in the memory when the distance measurement calculation is carried out,
wherein the computation processing circuit sequentially acquires the sensor data of each of the plurality of light receiving elements from the AF sensor, and at the same time sequentially generates the AF data generated from the acquired sensor data of each of the plurality of light receiving elements.
2. The distance measuring apparatus according to claim 1 , wherein the computation processing circuit sequentially stores the sensor data acquired from the AF sensor in the memory, generates the AF data according to the sensor data stored in the memory, and then stores the sensor data newly acquired from the AF sensor in an address of the memory in which the sensor data having been used for generating the AF data, and unnecessary for generating another AF data except for the generated AF data, is stored.
3. A distance measuring apparatus, comprising:
an AF sensor which forms images of light from a distance measurement object on a pair of line sensors comprising a plurality of light receiving elements and integrates signals obtained from the light receiving elements for each of the plurality of light receiving elements to generate a first and second sensor data which form a pair of sensor data, the second sensor data being shifted by two pixels from the first sensor data; and
a computation processing circuit which acquires the pair of sensor data generated by the AF sensor from the AF sensor, generates a pair of AF data for distance measurement calculation showing contrast of sensor images formed by the pair of line sensors by difference calculation processing according to the pair of sensor data, and calculates a distance from the distance measurement object according to the AF data,
wherein the computation processing circuit generates the AF data and stores the generated AF data in a memory before starting the distance measurement calculation, and uses the AF data stored in the memory when the distance measurement calculation is carried out,
wherein the computation processing circuit sequentially acquires the sensor data of each of the plurality of light receiving elements from the AF sensor, and at the same time sequentially generates the AF data generated from the acquired sensor data of each of the plurality of light receiving elements,
wherein the computation processing circuit sequentially stores the sensor data acquired from the AF sensor in the memory, generates the AF data according to the sensor data stored in the memory, and then stores the sensor data newly acquired from the AF sensor in an address of the memory in which the sensor data having been used for generating the AF data, and unnecessary for generating another AF data except for the generated AF data, is stored.