TWI382751B - Image capturing apparatus - Google Patents

Description

Camera

The present invention relates to an image pickup apparatus.

With the rapid development of electronic products, the application range of camera devices is becoming wider and wider. See Ahmed, S. et al., Emerging Technologies, 2007. ICET 2007. International Conference on, Monitoring Detection and Security Maintenance using WMS-Webcam Mobile Surveillance.

Previous camera devices are generally used during the day. When shooting objects at night, a flash is generally applied to the camera to illuminate the subject so that the shooting process proceeds normally. However, as the use range of the camera device is wider and wider, the required volume is also smaller and smaller. However, the additional light-emitting module greatly increases the volume of the camera device, which is disadvantageous to its development.

A small-sized imaging device will be described below by way of example.

An imaging device includes: an optical lens group, an image sensor, and a light emitting module. The light emitting module is disposed between the optical lens group and the image sensor. The light emitting module comprises a light emitting unit and an optical component opposite to the light emitting unit and having a transflective function. The optical element is configured to reflect light emitted by the light emitting unit to the optical lens group.

Compared with the prior art, the camera device has a light-emitting module, and the light emitted by the light-emitting unit is reflected by the optical component to the optical lens group, and is diffused to the object by the optical lens group to illuminate the object. In order to make the camera suitable for nighttime shooting. At the same time, the light-emitting module of the camera device is disposed between the optical lens group and the image sensor, and is located inside the camera device, which can effectively reduce the volume of the camera device.

The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

Referring to FIG. 1 , a first embodiment of the present invention provides an image pickup apparatus 100 including an optical lens group 10 , an image sensor 11 , and a light emitting module 12 .

The aperture factor F/# of the imaging apparatus 100 is a ratio of the focal length F of the imaging apparatus 100 to the diameter D of the lens aperture of the imaging apparatus 100, and is generally 2.4 F/# 4.0, preferably F/#=2.8. The relationship between the illuminance value E required by the image sensor 11 of the image capturing apparatus 100 and the aperture coefficient F/# satisfies the following condition: E=π TBY2/F12=π TB/2(F/#)2 (1) )

Where B is the object's brightness of the object projected on the image sensor 11.

T is the Transmission ration of webcam lens of the optical lens group 10.

F1 is an equivalent focal length.

Y is 1/2 of the aperture size d that the imaging device 100 can take.

F/# is the aperture factor of the imaging apparatus 100.

The light emitting module 12 is disposed between the optical lens group 10 and the image sensor 11 . The light emitting module 12 includes a light emitting unit 121 and an optical component 122 disposed opposite to the light emitting unit 121. In this embodiment, the optical lens group 10, the optical component 122, and the image sensor 11 are arranged in a straight line. The line connecting the light emitting unit 121 and the optical element 122 is perpendicular to the straight line.

The light emitting unit 121 can be a light emitting diode chip, a light emitting diode or a light emitting diode module. The minimum illuminance value of the illuminating unit 121 is selected according to the illuminance value E required by the image sensor 11. Preferably, the light emitted by the light emitting unit 121 is white light.

Specifically, in the present embodiment, when the illumination module 12 is not applied with the aperture coefficient F/#=2.8 of the imaging device 100, the imaging device 100 can normally capture the object and the object is reflected. The illuminance value is a first unit value, and the value is 1, and the illuminance value E sensed by the image sensor 11 is the second unit value 1.

When the environment is changed, the illuminance value E sensed by the image sensor 11 needs to be increased to 1.96 times the second unit value, that is, when the improved ratio value of the image sensor 11 is 1.96, at least the object needs to be reflected. The illuminance value is increased to 1.96 times the first unit value.

Generally, it is realized by adjusting the value of the aperture coefficient F/#. When the aperture coefficient F/#=2.0, the illuminance value E sensed by the image sensor 11 can be increased to 1.96 times of the second unit value. However, due to the decrease in the aperture factor F/# value This may cause the contrast of the image pickup apparatus 100 to deteriorate, thereby deteriorating the sharpness of the image. Moreover, the larger the improvement ratio value of the image sensor 11 is, the smaller the aperture coefficient F/# needs to be, and the worse the resolution of the image is.

Therefore, in the embodiment, the aperture coefficient F/# of the camera device 100 is not adjusted, that is, the aperture coefficient F/# is still 2.8, and the object is increased by adding a light-emitting module 12 in the camera device 100. The amount of illuminance reflected. The minimum illumination value required by the illumination unit 121 of the illumination module 12 is 1.96 times the first unit value, because the illumination value E sensed by the image sensor 11 needs to be increased to 1.96 times the second unit value. That is, the minimum illumination ratio required for the light-emitting unit 121 is 1.96.

Of course, when the illuminance value E sensed by the image sensor 11 needs to be increased to other values, the selection of the minimum illuminance value required by the illumination unit 121 added by the camera device 100 can be found in the following table.

According to the above table, the minimum illumination ratio value required for the illumination unit 121 is equal to the illumination improvement ratio value required by the image sensor 11 of the imaging apparatus 100. Therefore, the minimum illuminance value E required by the image sensor 11 of the image capturing apparatus 100 is calculated according to the formula (1), and the required illuminance improvement ratio value of the image sensor 11 can be obtained, thereby obtaining the light emitting unit. 121 Minimum required illumination ratio value.

Of course, the reference value is not limited to the aperture coefficient F/#=2.8 of the imaging device 100, and may be other values, thereby obtaining other different minimum illumination ratio values of the illumination unit 121, which may be specifically selected according to implementation conditions. .

The optical element 122 has a function of transflective reflection, and the optical element 122 is configured to reflect the light emitted by the light emitting unit 121 to the optical lens group 10. Preferably, the optical element 122 is a beam splitter.

Referring to FIG. 2, when the image capturing apparatus 100 is used, light emitted by the light emitting unit 121 is incident on the optical element 122. Since the optical element 122 has a transflective function, part of the light is worn by the optical element 122. After the light is transmitted out, the remaining light is reflected on the optical element 122 and uniformly emitted by the optical lens group 10 to be irradiated onto the object 20. At the same time, the light emitted by the light-emitting unit 121 is reflected by the object 20, enters the image capturing device 100 through the optical lens group 10, and finally is irradiated to the image sensor 11 through the optical element 122, and the image is applied to the image. An image is formed on the sensor 11, thereby completing the photographing process.

Since the image capturing device 100 has the light emitting module 12, the light emitted by the light emitting module 12 is reflected by the optical element 122 to the optical lens group 10, and the optical lens group 10 uniformly emits light to the surface of the object 20, The illumination of the surface of the subject 20 is made stronger and the brightness is uniform, so that the imaging apparatus 100 is suitable for nighttime shooting. At the same time, the light-emitting module 12 of the camera device 100 is disposed between the optical lens unit 10 and the image sensor 11 and is located inside the image-capturing device 100. The volume of the image pickup apparatus 100 is effectively reduced, which is suitable for the development trend of the image pickup apparatus 100.

The optical element 122 has a transflective function, and when the light emitted by the light emitting unit 121 passes through the optical element 122, part of the light will penetrate the optical element 122. In order to prevent the light from affecting the imaging of the image sensor 11, a protection device may be disposed between the optical component 122 and the image sensor 11 for preventing excessive light from being incident on the image sensor 11, thereby making the shooting process Going smoothly. Of course, the light-emitting module 12 can also be a movable design, and the light-emitting module 12 can be removed when the light can maintain normal shooting, thereby preventing excessive light from being irradiated to the image sensor 11.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by persons skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims.

100‧‧‧ camera

10‧‧‧Optical lens group

11‧‧‧Image Sensor

12‧‧‧Lighting module

121‧‧‧Lighting unit

122‧‧‧Optical components

20‧‧‧Photographed object

FIG. 1 is a schematic diagram of an image pickup apparatus according to an embodiment of the present invention.

2 is a schematic view of the optical path of the image pickup device provided in FIG. 1.

100‧‧‧ camera

10‧‧‧Optical lens group

11‧‧‧Image Sensor

12‧‧‧Lighting module

121‧‧‧Lighting unit

122‧‧‧Optical components

Claims (7)

An image pickup device includes: an optical lens group and an image sensor, wherein the image pickup device further includes a light emitting module disposed between the optical lens group and the image sensor And the light emitting module is a movable design, the light emitting module includes a light emitting unit and an optical component opposite to the light emitting unit and having a transflective function, wherein the optical component is used to emit light from the light emitting unit Reflected to the optical lens group. The image pickup device of claim 1, wherein the light emitting unit comprises a light emitting diode chip, a light emitting diode or a light emitting diode module. The imaging device according to claim 1, wherein the aperture coefficient F/# of the imaging device is 2.4 F/# 4.0. The image pickup device according to claim 1, wherein the optical element is a beam splitter. The image pickup device of claim 1, wherein the light emitted by the light emitting module is white light. The camera device of claim 1, wherein the minimum illumination ratio required for the illumination module is equal to the illumination improvement ratio required by the image sensor of the camera. The image pickup device of claim 1, wherein the optical lens group, the optical element, and the image sensor are arranged in a straight line, and the line connecting the light unit and the optical element is perpendicular to the line. .