Image capturing apparatus

Abstract

An image capturing apparatus illuminates an object and captures an image of the object using the reflected light from the object. On a circuit substrate mounted an image sensor, a plurality of light-emitting devices are mounted in the peripheral positions of the image sensor. By means of a ring-shaped light guide member, the light from the plurality of light-emitting devices is guided to an image capturing range, so as to illuminate the object. With this, by mounting a light receiving system and a light emitting system on an identical substrate, miniaturization can be achieved, and the image capturing range can be illuminated by substantially uniform light. Also, using the ring-shaped light guide member, an optical unit is housed inside the ring, thus enabling further miniaturization.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a cross-sectional view of an image capturing apparatus according to one embodiment of the present invention.

FIG. 2 shows an exploded structural view of the image capturing apparatus shown in FIG. 1.

FIG. 3 shows a component layout diagram of the circuit board shown in FIG. 2.

FIG. 4 shows an explanation diagram of the relationship between a light-emitting device and a photodetector device shown in FIG. 2.

FIG. 5 shows an assembly diagram of the decomposed components shown in FIG. 2.

FIG. 6 shows a configuration diagram of the external finishing components shown in FIG. 1.

FIG. 7 shows a configuration diagram of the assembly of the assembled body shown in FIG. 2.

FIG. 8 shows an outer view of the image capturing apparatus shown in FIG. 1.

FIG. 9 shows an explanation diagram of the illumination system shown in FIG. 1.

FIG. 10 shows a configuration diagram of the light guide member and the light-emitting device shown in FIG. 9.

FIG. 11 shows a relation diagram of the emission intensity distribution of the light-emitting device, and the lower end portion of the light guide member shown in FIG. 10.

FIG. 12 shows a first operation explanation diagram of the light guide member shown in FIG. 10.

FIG. 13 shows a second operation explanation diagram of the light guide member shown in FIG. 10.

FIG. 14 shows a third operation explanation diagram of the light guide member shown in FIG. 10.

FIG. 15 shows a light intensity distribution diagram using the light guide member shown in FIG. 10.

FIG. 16 shows a block diagram of a control circuit for the image capturing apparatus shown in FIG. 1.

FIG. 17 shows an image capturing process flowchart of the control circuit shown in FIG. 16.

FIG. 18 shows an explanation diagram of distance measurement operation using the configuration shown in FIG. 16.

FIG. 19 shows an explanation diagram of the conventional palm image capturing apparatus.

FIG. 20 shows a principle explanation diagram of the conventional palm image capturing apparatus.

FIG. 21 shows an explanation diagram of the conventional palm authentication technique.

FIG. 22 shows another explanation diagram of the conventional palm authentication technique.

FIG. 23 shows an explanation diagram of an illumination configuration in the conventional image capturing apparatus.

FIG. 24 shows a configuration diagram of the conventional image capturing apparatus.

Claims

1. An image capturing apparatus for capturing an image of an object by illuminating the object and receiving reflected light from the object, comprising: a circuit board mounted an image sensor for receiving the reflected light;a plurality of light-emitting devices mounted on the circuit board in the peripheral positions of the image sensor;a ring-shaped light guide member for guiding the light emitted from the plurality of light-emitting devices, and illuminating an image capturing range; andan optical unit housed inside the ring of the ring-shaped light guide member and for guiding the reflected light from the illuminated object in the image capturing range to the image sensor.

2. The image capturing apparatus according to claim 1, wherein the plurality of light-emitting devices are mounted on the circuit board at predetermined intervals, along a circle in the periphery of the image sensor, and wherein the light guide member is formed of a ring shape corresponding to the circle.

3. The image capturing apparatus according to claim 1, further comprising a diffusion plate for diffusing the light of the light-emitting devices and provided between the ring-shaped light guide member and the plurality of light-emitting devices.

4. The image capturing apparatus according to claim 1, further comprising a photo-detector device for monitoring the light of the light-emitting devices and provided between each of the plurality of light-emitting devices on the circuit board.

5. The image capturing apparatus according to claim 1, further comprising a distance-measuring light-emitting device mounted on the circuit board so as to measure a distance to the object.

6. The image capturing apparatus according to claim 1, wherein the plurality of light-emitting devices are constituted of light-emitting devices emitting infrared light, and wherein further comprises an optical filter for cutting off visible light and provided at least on the incident plane of the optical unit.

7. The image capturing apparatus according to claim 1, wherein the plurality of light-emitting devices comprises: first light-emitting devices for emitting light of a first wavelength; andsecond light-emitting devices for emitting light of a second wavelength different from the first wavelength,and wherein the first light-emitting devices and the second light-emitting devices are disposed alternately along a circle in the periphery of the image sensor on the circuit board.

8. The image capturing apparatus according to claim 7, further comprising photo-detector devices for monitoring the light of the first and second light-emitting devices and provided between each first light-emitting device and each second light-emitting device on the circuit board.

9. The image capturing apparatus according to claim 1, wherein the light guide member comprises: a lower end portion for introducing the light of the light-emitting devices;an upper end portion for outputting the light to the image capturing range; anda light guide portion for guiding the light of the light-emitting devices from the lower end portion to the upper end portion.

10. The image capturing apparatus according to claim 4, wherein the photodetector device is provided in a position for receiving the reflected light at a lower portion of the light guide member among the light emitted from the light-emitting devices.

11. The image capturing apparatus according to claim 3, wherein the diffusion plate is constituted of a plurality of separate diffusion members, corresponding to the plurality of light-emitting devices being mounted on the circuit board at predetermined intervals along the circle in the periphery of the image sensor.

12. The image capturing apparatus according to claim 5, wherein the distance-measuring light-emitting device is mounted on the circuit board in such a position as to measure the distance to the object in the image capturing range, from the image of the image sensor.

13. The image capturing apparatus according to claim 12, wherein the distance-measuring light-emitting device is mounted on the circuit board in an outer position of the light-emitting devices.

14. The image capturing apparatus according to claim 1, wherein the image sensor images a portion of a living body.