TWI479888B - Image-detecting device and image-detecting method - Google Patents

Description

Image sensing device and image sensing method

The present invention relates to an image sensing device and an image sensing method, and more particularly to an image sensing device and an image sensing method capable of adjusting an image output frequency according to a light sensing time.

Generally, an image capturing device such as a camera or a scanner includes an image sensing device. After the sensing component in the image sensing device senses the image in a sensing time, the sensing component senses at an output frequency. The measured image is output to a register. Please refer to FIG. 1. FIG. 1 is a timing diagram of a sensing time t, an output frequency clock signal c, and an output image signal I of a conventional image sensing device. In the conventional image sensing device, the clock signal c of the output frequency is a fixed value, regardless of the length of the sensing time, and the image signal sensed by the sensing component can be output to the sensing time in different sensing times. In the register, the output frequency corresponding to the clock signal c of the output frequency is mostly high frequency. The high-frequency output frequency causes the image signal to be output to the scratchpad much earlier than before the next light-sensing start, resulting in unnecessary energy waste, and the image noise value caused by the high frequency is also large.

In summary, how to develop an image sensing device to effectively reduce energy consumption and image noise to obtain better image quality is an urgent task.

The invention provides an image sensing device and an image sensing method, which can adjust the image output frequency according to the light sensing time, so as to effectively reduce image noise and obtain better image quality.

An image sensing device according to an embodiment of the invention includes a controller, a clock generator and an image sensing component, wherein the controller determines a first sensing time and a corresponding first output frequency. The clock generator is electrically connected to the controller, and the clock generator generates a clock signal of the first output frequency according to the first output frequency. The image sensing component is electrically connected to the controller and the clock generator. The image sensing component senses the image during the first sensing time to generate an image signal, and outputs the image signal with the clock signal of the first output frequency.

An image sensing method according to another embodiment of the present invention includes: sensing light during a first sensing time, and generating an image signal; generating a corresponding first output frequency according to the length of the first sensing time And generating a clock signal of the first output frequency according to the first output frequency; and outputting the image signal with the clock signal of the first output frequency.

The above and other aspects, features and advantages of the present invention will become more apparent from the description of the appended claims.

Please refer to FIG. 2a. FIG. 2a is a schematic diagram showing an image sensing device according to an embodiment of the present invention, which includes a controller 11, a clock generator 12 and an image sensing component 13. The controller 11 determines a first light sensing time t ₁ and a corresponding first output frequency f ₁ . The clock generator 12 is electrically connected to the controller 11, a clock signal and a first output a first frequency, c ₁ is generated according to the output frequencies f _1. The image sensing component 13 can be a Charge Coupled Device (CCD), a Complementary Metal Oxide Semiconductor (CMOS) sensor, or a Contact Image Sensor (CIS). It is electrically connected to the controller 11 and the clock generator 12. The image sensing component 13 senses the image during the first sensing time t ₁ to generate an image signal I, and outputs the image signal I at the clock signal c _{1 of the} first output frequency.

In one embodiment, the first sensing time t ₁ is determined according to the intensity of the image signal generated by the image sensing component 13 during a predetermined sensing time. For example, the controller 11 controls the image sensing component 13 to sense an image during a predetermined sensing time, and outputs the generated image signal to the controller 11 if the intensity of the image signal generated during the preset sensing time exceeds A threshold value, the value of the first photosensitive time t ₁ generated by the controller 11 will be less than the preset photosensitive time. In another embodiment, as shown in FIG. 2b, the image sensing device further includes a photometric component 14 electrically connected to the controller 11 for sensing brightness and generating a first brightness parameter p ₁ to the controller 11 . The controller 11 generates a first photosensitive luminance times t ₁ according to a first parameter p _1. In another embodiment, the image sensing device further includes a light emitting component for providing a light source to provide sufficient light amount for image sensing, wherein the light emitting component can be a light emitting diode or a cold cathode fluorescent tube. .

It is to be noted that the controller 11 generates a corresponding output frequency according to the length of the photosensitive time. Please refer to FIG. 3 at the same time. FIG. 3 is a diagram showing a first sensing time t ₁ , a second sensing time t ₂ , a clock signal c _{1 of the} first output frequency, and a second output of the image sensing device according to the embodiment of the invention. Timing diagram of frequency clock signal c ₂ and image signal I, I'. The controller 11 generates a second sensing time t ₂ and a second output frequency (not labeled). In the embodiment shown in FIG. 3, the second photosensitive time t _{2 is} greater than the first photosensitive time t ₁ , and the second output frequency (not labeled) generated by the controller 11 according to the second photosensitive time t _{2 is} smaller than the first output frequency f ₁ . Therefore, the image sensing component 13 outputs the image signal I' by the clock signal c ₂ of the second output frequency generated by the clock generator 12. Conversely, when the second photosensitive time t _{2 is} less than the first photosensitive time t ₁ , the second output frequency (not labeled) generated by the controller 11 according to the second photosensitive time t _{2 is} greater than the first output frequency f ₁ . The image sensing component 13 outputs the image signal I' by the clock signal c ₂ of the second output frequency generated by the clock generator 12.

It should be noted that the image sensing component 13 is within the first sensing time t ₁ (second sensing time t ₂ ), and the clock signal c _{1 of the} first output frequency (the clock signal c _{2 of the} second output frequency) The signal corresponding to each cycle is output with the image signal I(I'). That is to say, when the sensing time is long, the controller 11 will determine a lower output frequency, and the image signal can be output in time without the high-frequency output, thereby avoiding unnecessary energy waste and effectively reducing image noise. For better image quality.

Please refer to FIG. 1 and FIG. 4 simultaneously. FIG. 4 is a flow chart showing an image sensing method according to an embodiment of the invention. First, the light is sensed during the first photosensitive time t ₁ and the image signal I is generated (S1); the corresponding first output frequency f ₁ (S2) is generated according to the length of the first photosensitive time t ₁ ; according to the first output The frequency f ₁ generates a clock signal c _{1 of the} first output frequency (S3); then, the image sensing element 13 outputs the image signal I (S4) with the clock signal c _{1 of the} first output frequency. The first sensing time t ₁ is determined according to the above, according to the intensity of the image signal generated by the image sensing component 13 during a predetermined sensing time, or by using the metering in the embodiment of FIG. 2b. Element 14 performs metering to determine the first photosensitive time t ₁ . In addition, in an embodiment, further comprising providing a light source to provide sufficient light amount for sensing. It should be noted that, in the image sensing method of the present invention, the corresponding output frequency and the clock signal are generated according to the length of the sensing time, which is the same as the image sensing device of the present invention described above, and will not be described herein.

In summary, the image sensing device and the image sensing method of the present invention generate a corresponding output frequency and a clock signal according to the length of the sensing time, so that the signals corresponding to each period of the clock signal of different output frequencies are output. Information with video signals. When the sensing time is long, a lower output frequency can be determined, and the image signal can be output in time without the high-frequency output, which not only avoids unnecessary energy waste, but also effectively reduces image noise and obtains better images. quality.

The embodiments described above are only intended to illustrate the technical idea and the features of the present invention, and the purpose of the present invention is to enable those skilled in the art to understand the contents of the present invention and to implement the present invention. That is, the equivalent variations or modifications made by the spirit of the present invention should still be included in the scope of the present invention.

11. . . Controller

12. . . Clock generator

13. . . Image sensing component

14. . . Metering element

t. . . Sensing time of conventional technology

t ₁ . . . First light sensing time

t ₂ . . . Second light sensing time

f ₁ . . . First output frequency

c. . . Clock signal of the output frequency of the prior art

c ₁ . . . Clock signal of the first output frequency

c ₂ . . . Clock signal of the second output frequency

p ₁ . . . First brightness parameter

I, I’. . . Image signal

S1-S4. . . step

FIG. 1 is a timing diagram showing a clock signal of a photosensitive time and an output frequency of a conventional image sensing device and an output image signal.

2a is a schematic diagram showing an image sensing device in accordance with an embodiment of the present invention.

2b is a schematic diagram showing an image sensing device according to another embodiment of the present invention.

3 is a timing diagram showing a first sensing time, a second sensing time, a clock signal of a first output frequency, and a clock signal of a second output frequency and an image signal according to an embodiment of the present invention.

4 is a flow chart showing an image sensing method according to an embodiment of the invention.

S1-S4. . . step

Claims (10)

An image sensing device includes: a controller that determines a first sensing time and a corresponding first output frequency; a clock generator electrically coupled to the controller, the clock generator according to the The first output frequency generates a clock signal of a first output frequency; and an image sensing component electrically connected to the controller and the clock generator, the image sensing component sensing in the first sensing time The image is used to generate an image signal, and the image signal is outputted by the clock signal of the first output frequency. The image sensing device of claim 1, wherein the controller further determines a second sensing time and a second output frequency, and the clock generator generates a clock of the second output frequency according to the second output frequency. a signal, the image sensing component outputs the image signal by the clock signal of the second output frequency, wherein the second sensing time is greater than the first sensing time, and the second output frequency is less than the first output frequency; or The second sensing time is less than the first sensing time, and the second output frequency is greater than the first output frequency. The image sensing device of claim 1, further comprising a photometric component electrically coupled to the controller for sensing brightness and generating a first brightness parameter to the controller, the controller according to the first The brightness parameter determines the first light sensing time and the first output frequency. The image sensing device of claim 1, wherein the image sensing device comprises a Charge Coupled Device (CCD), a Complementary Metal Oxide Semiconductor (CMOS) sensor or a contact. Contact Image Sensor (CIS). The image sensing device of claim 1, further comprising a light emitting element for providing a light source. The image sensing device of claim 5, wherein the light emitting element comprises a light emitting diode or a cold cathode fluorescent tube. An image sensing method includes: sensing a light during a first sensing time, and generating an image signal; generating a corresponding first output frequency according to the length of the first sensing time; generating according to the first output frequency a first output frequency clock signal; and outputting the image signal by the clock signal of the first output frequency. The image sensing method of claim 7, further comprising: sensing light in a second sensing time, and generating the image signal; generating a corresponding second output frequency according to the length of the second sensing time; And outputting the image signal at the second output frequency, wherein the second sensing time is greater than the first sensing time, and the second output frequency is less than the first output frequency; or the second sensing time is less than the first sensing time Time, and the second output frequency is greater than the first output frequency. The image sensing method of claim 7, wherein the first sensing time is determined according to the intensity of the image signal generated during a predetermined sensing time. The image sensing method of claim 7, further comprising the step of providing a light source.