Image acquisition apparatus, terminal device, liquid crystal terminal device and image acquisition method
An image acquisition apparatus, a terminal device, a liquid crystal terminal device and an image acquisition method are provided according to the disclosure. The image acquisition apparatus includes an imaging plate and an image sensor disposed to be spaced apart from one side of the imaging plate. The imaging plate is provided with an imaging pinhole corresponding to the image sensor. The liquid crystal terminal device includes an LCD panel and a backlight element. The image acquisition apparatus is disposed at a position corresponding to the LCD panel within the backlight element. The image acquisition method includes acquiring an image of an object to being scanned by the image sensor through the imaging pinhole at a side of the imaging panel. An ultrathin fingerprint scanner can be formed based on pinhole imaging principle in the disclosure, and can be further combined with an LCD screen to accomplish fingerprint acquisition function. Alternatively, an ultrathin image acquisition device can be formed to acquire an image of a general object. This can significantly reduce the size and thickness of an image acquisition module in the device and greatly facilitate the implementation of mobile devices and embedded devices with an image acquisition function.
1. An image acquisition apparatus comprising:
an imaging plate and one or more image sensors disposed to be spaced apart from one side of the imaging plate, wherein the imaging plate is provided with at least one imaging pinhole corresponding to the image sensors, and light through the imaging pinholes is imaged by the image sensors,
wherein a distance from an object being scanned to a center plane of the imaging plate is an object distance h object , and the object distance h object satisfies a formula of
h
object
≥
2
r
2
tg
(
α
/
2
)
,
wherein r represents a distance between centers of two adjacent imaging pinholes, and α represents an angular field of view of the imaging pinholes.
2. A terminal device, comprising: a display screen, wherein the display screen comprises a display panel and a backlight element, wherein the backlight element comprises a reflective sheet, a back plate and at least one layer of optical film disposed between the display panel and the reflective sheet, and the image acquisition apparatus according to claim 1 is disposed between the reflective sheet and the back plate, or below the back plate; and the field of view of the image acquisition apparatus between an object being scanned and the image acquisition apparatus is not blocked for imaging.
3. An image acquisition apparatus comprising:
an imaging plate and one or more image sensors disposed to be spaced apart from one side of the imaging plate, wherein the imaging plate is provided with at least one imaging pinhole corresponding to the image sensors, and light through the imaging pinholes is imaged by the image sensors,
wherein a distance r between centers of two adjacent imaging pinholes satisfies a formula of r≥2·h image tg(α/2), wherein h image represents an image distance, which is a distance from the image sensor to a center plane of the imaging plate, and α represents an angular field of view of the imaging pinholes.
4. A terminal device, comprising:
a display screen, wherein the display screen comprises a display panel and a backlight element, wherein the backlight element comprises a reflective sheet, a back plate and at least one layer of optical film disposed between the display panel and the reflective sheet, and the image acquisition apparatus according to claim 3 is disposed between the reflective sheet and the back plate, or below the back plate; and the field of view of the image acquisition apparatus between an object being scanned and the image acquisition apparatus is not blocked for imaging.
5. An image acquisition method for the terminal device according to claim 4 , comprising:
putting a display panel into a transparent state in response to a control signal; and
establishing multiple scanning regions for one object being scanned, wherein adjacent scanning regions are overlapping with each other; and
capturing partial images of the object being scanned in the scanning regions by the image sensor through the imaging pinholes, wherein partial images in adjacent imaging regions do not overlap with each other; and
stitching together the partial images in all imaging regions to obtain a complete image of the object being scanned.
6. A terminal device, comprising a display screen, wherein the display screen comprises a display panel and a backlight element, wherein the backlight element comprises a reflective sheet, a back plate and at least one layer of optical film disposed between the display panel and the reflective sheet,
wherein an image sensor is disposed between the reflective sheet and the back plate, and one or more imaging pinholes are disposed on the reflective sheet at a position corresponding to the image sensor, the reflective sheet being also used as an imaging plate; or
the image sensor is disposed below the back plate, and one or more imaging pinholes are disposed through the reflective sheet and the back plate at a position corresponding to the image sensor, the reflective sheet and the back plate being also used as an imaging plate,
wherein the field of view of the image sensor between an object being scanned and the image sensor is not blocked for imaging,
wherein a distance from the object being scanned to a center plane of the imaging plate is an object distance h object , and the object distance h object satisfies a formula of
h
object
≥
2
r
2
tg
(
α
/
2
)
,
wherein r represents a distance between centers of two adjacent imaging pinholes, and α represents an angular field of view of the imaging pinholes.
7. An image acquisition method for an image acquisition apparatus comprising an imaging plate and one or more image sensors disposed to be spaced apart from one side of the imaging plate, wherein the imaging plate is provided with at least one imaging pinhole corresponding to the image sensors, and light through the imaging pinholes is imaged by the image sensors, the method comprising:
establishing multiple scanning regions for one object being scanned, wherein adjacent scanning regions are overlapping with each other;
capturing partial images of the object being scanned in the scanning regions by the image sensor through the imaging pinholes, wherein partial images in adjacent imaging regions do not overlap with each other; and
stitching together the partial images in all imaging regions to obtain a complete image of the object being scanned.
8. An image acquisition method for the terminal device according to any one of claims 2 - 3 , comprising:
putting a display panel into a transparent state in response to a control signal; and
establishing multiple scanning regions for one object being scanned, wherein adjacent scanning regions are overlapping with each other; and
capturing partial images of the object being scanned in the scanning regions by the image sensor through the imaging pinholes, wherein partial images in adjacent imaging regions do not overlap with each other; and
stitching together the partial images in all imaging regions to obtain a complete image of the object being scanned.