CN102811319A - Image sensing device and image sensing method - Google Patents

Abstract

An image sensing device and an image sensing method generate corresponding output frequency and clock pulse signals according to the length of the light sensing time. When the photosensitive time is longer, a lower output frequency can be determined, and the image signal can be output in time without high-frequency output, so that unnecessary energy waste can be avoided, the image noise can be effectively reduced, and better image quality can be obtained.

Description

Image sensing device and image sensing method

technical field

The present invention relates to an image sensing device and an image sensing method, in particular to an image sensing device and an image sensing method capable of adjusting the image output frequency according to the photosensitive time.

Background technique

A generally known image capture device such as a camera or a scanner includes an image sensing device. After the sensing element in the image sensing device senses an image within a light-sensing time, the sensing element outputs the sensing element with an output frequency The measured image is output to a buffer. Please refer to FIG. 1 . FIG. 1 is a timing diagram of a known photosensitive time t, a clock signal c of an output frequency, and an output image signal I of a known image sensing device. In a generally known image sensing device, the clock signal c of the output frequency is a fixed value, which has nothing to do with the length of the photosensitive time, and in order to enable the image signal sensed by the sensing component to be output in time under different photosensitive times In the register, the output frequency corresponding to the clock signal c of the output frequency is mostly a high frequency. The high-frequency output frequency causes all the image signals to be output to the buffer much earlier than the start of the next exposure, resulting in unnecessary waste of energy, and the image noise value caused by the high frequency is also relatively large.

To sum up, how to develop an image sensing device to effectively reduce energy consumption and image noise to obtain better image quality is a goal that requires great efforts.

Contents of the invention

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

An image sensing device according to an embodiment of the present invention includes a controller, a clock generator and an image sensing component, wherein the controller determines a first photosensitive 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 a 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 an image within the first photosensitive time to generate an image signal, and outputs the image signal with the clock signal of the first output frequency.

The image sensing method according to another embodiment of the present invention includes: sensing light within a first photosensitive time and generating an image signal; generating a corresponding first output frequency according to the length of the first photosensitive time ; Generate a clock signal with a first output frequency according to the first output frequency; and output an image signal with the clock signal at the first output frequency.

The above and other aspects, characteristics and advantages of the present invention can be better understood from the accompanying drawings and descriptions of the embodiments.

Description of drawings

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

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

FIG. 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 photosensitive time, a second photosensitive time, a clock signal of a first output frequency, a clock signal of a second output frequency, and an image signal of an image sensing device according to an embodiment of the present invention.

FIG. 4 is a flowchart showing an image sensing method according to an embodiment of the invention.

Description of main component symbols:

11 controller

12 clock generators

13 Image sensing components

14 Metering components

t Photosensitive time of known technology

t ₁ first photosensitive time

t ₂ second photosensitive time

f ₁ first output frequency

c The clock signal of the output frequency of the known technology

c ₁ clock signal of the first output frequency

c ₂ The clock signal of the second output frequency

p ₁ first brightness parameter

I, I' image signal

S1-S4 steps

Detailed ways

Please refer to FIG. 2 a . FIG. 2 a 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 photosensitive time t ₁ and a corresponding first output frequency f ₁ . The frequency generator 12 is electrically connected to the controller 11 and generates a clock signal c ₁ of a first output frequency according to the first output frequency f ₁ . The image sensing element 13 can be a charge coupled device (Charge Coupled Device, CCD), a complementary metal oxide semiconductor (Complementary Metal Oxide Semiconductor, CMOS) sensor or a contact image sensor (Contact Image Sensor, CIS). The controller 11 and the clock generator 12 are connected. The image sensing component 13 senses an image within the first photosensitive time _t1 to generate an image signal I, and outputs the image signal I with the clock signal _c1 of the first output frequency.

In one embodiment, the first light-sensing time _t1 is determined according to the intensity of the image signal generated by the image sensing element 13 within a preset light-sensing time. For example, the controller 11 controls the image sensing element 13 to sense an image within a preset photosensitive time, and output the generated image signal to the controller 11, if the intensity of the generated image signal within the preset photosensitive time exceeds If there is a threshold value, the value of the first light-sensing time _t1 generated by the controller 11 will be smaller than the preset light-sensing time. In another embodiment, as shown in FIG. 2b, the image sensing device further includes a light metering component 14, which is electrically connected to the controller 11, for sensing brightness and generating a first brightness parameter _p1 to the controller 11. The controller 11 generates a first photosensitive time t ₁ according to the first brightness parameter p ₁ . In another embodiment, the image sensing device further includes a light emitting element for providing a light source to provide sufficient light for image sensing, wherein the light emitting element can be a light emitting diode or a CCFL.

It should 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 shows the first light-sensing time t ₁ , the second light-sensing time t ₂ , the clock signal c ₁ of the first output frequency, and the second output of the image sensing device according to an embodiment of the present invention. Timing diagram of frequency clock signal c ₂ and image signals I, I'. The controller 11 generates a second photosensitive time t ₂ and a second output frequency (not shown). In the embodiment shown in FIG. 3 , the second light-sensing time t ₂ is greater than the first light-sensing time t ₁ , and the second output frequency (not marked) generated by the controller 11 according to the second light-sensing time t ₂ is smaller than the first output frequency f ₁ . Therefore, the image sensing component 13 outputs the image signal I′ with the clock signal c ₂ of the second output frequency generated by the clock generator 12 . Conversely, when the second light-sensing time t ₂ is shorter than the first light-sensing time t ₁ , the second output frequency (not shown) generated by the controller 11 according to the second light-sensing time t ₂ is greater than the first output frequency f ₁ . The image sensing component 13 outputs the image signal I′ according to the clock signal c ₂ of the second output frequency generated by the clock generator 12 .

It should be noted that, within the first light-sensing time t ₁ (second light-sensing time t ₂ ) of the image sensing component 13 , the clock signal c ₁ of the first output frequency (the clock signal c ₂ of the second output frequency) The output signal corresponding to each cycle carries the data of the image signal I(I′). That is to say, when the photosensitive time is longer, the controller 11 will determine a lower output frequency, and the image signal can be output in time without high-frequency output, which can not only avoid unnecessary waste of energy, but also effectively reduce image noise , to obtain better image quality.

Please refer to FIG. 1 and FIG. 4 at the same time. FIG. 4 is a flowchart showing an image sensing method according to an embodiment of the present invention. First, light is sensed within the first photosensitive time _t1 , and an image signal I (S1) is generated; a corresponding first output frequency _f1 is generated according to the length of the first photosensitive time _t1 (S2); 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 component 13 outputs the image signal I with the clock signal c ₁ of the first output frequency ( S4 ). Wherein, the determination method of the first light-sensing time _t1 is determined according to the intensity of the image signal generated by the image sensing element 13 within a predetermined light-sensing time, as mentioned above, or by using the measuring method in the embodiment of FIG. 2b The light component 14 measures light to determine the first light-sensing time t ₁ . In addition, in one embodiment, it further includes providing a light source to provide sufficient light for sensing. It should be noted that in the image sensing method of the present invention, the corresponding output frequency and clock signal are generated according to the length of the photosensitive time, which is the same as the image sensing device of the present invention described above, and will not be repeated here.

To sum up the above, the image sensing device and the image sensing method of the present invention generate corresponding output frequency and clock signal according to the length of photosensitive time, so that the output signal corresponding to each cycle of the clock signal with different output frequency is Data with video signals. When the photosensitive time is long, a lower output frequency can be determined, and the image signal can be output in time without high-frequency output, which can not only avoid unnecessary energy waste, but also effectively reduce image noise and obtain better image quality .

The above-described embodiments are only for illustrating the technical ideas and characteristics of the present invention, and its purpose is to enable those who are familiar with this art to understand the content of the present invention and implement it accordingly. When it is impossible to limit the patent scope of the present invention, That is, all equivalent changes or modifications made according to the spirit disclosed in the present invention should still be covered within the patent scope of the present invention.

Claims (10)

1. Image sensor apparatus is characterized in that it comprises:

One controller, it determines one first sensitive time and corresponding first output frequency;

One clock pulse generator, it electrically connects this controller, and this clock pulse generator produces the clock signal of one first output frequency according to this first output frequency; And

One image sensing component, it electrically connects this controller and this clock pulse generator, and this image sensing component is sensing image in this first sensitive time, in order to producing a signal of video signal, and exports this signal of video signal with the clock signal of this first output frequency.

2. Image sensor apparatus as claimed in claim 1; It is characterized in that; This controller more determines one second sensitive time and one second output frequency, and this clock pulse generator is according to the clock signal of this this second output frequency of second output frequency generation, and this image sensing component is with this this signal of video signal of clock signal output of this second output frequency; Wherein this second sensitive time is greater than this first sensitive time, and this second output frequency is less than this first output frequency; Or this second sensitive time is less than this first sensitive time, and this second output frequency is greater than this first output frequency.

3. Image sensor apparatus as claimed in claim 1; It is characterized in that; More comprise a photometry assembly; It electrically connects this controller, and in order to sensing brightness and produce one first luminance parameter to this controller, this controller is according to this first luminance parameter this first sensitive time of decision and this first output frequency.

4. Image sensor apparatus as claimed in claim 1 is characterized in that this image sensing component comprises a Charged Coupled Device, CMOS semiconductor sensor or contact image sensor.

5. Image sensor apparatus as claimed in claim 1 is characterized in that, more comprises a luminescence component, in order to light source to be provided.

6. Image sensor apparatus as claimed in claim 5 is characterized in that, this luminescence component comprises a light-emitting diode or a cathode fluorescent tube.

7. an image sensing method is characterized in that, comprises:

Light sensing in one first sensitive time, and produce a signal of video signal;

Length according to this first sensitive time produces corresponding one first output frequency;

Produce the clock signal of one first output frequency according to this first output frequency; And

This signal of video signal of clock signal output with this first output frequency.

8. image sensing method as claimed in claim 7 is characterized in that, more comprises:

Light sensing in one second sensitive time, and produce this signal of video signal;

Length according to this second sensitive time produces corresponding one second output frequency; And

With this signal of video signal of this second output frequency output, wherein this second sensitive time is greater than this first sensitive time, and this second output frequency is less than this first output frequency; Or this second sensitive time is less than this first sensitive time, and this second output frequency is greater than this first output frequency.

9. image sensing method as claimed in claim 7 is characterized in that, be that the intensity that is pursuant to this signal of video signal that is produced in the preset sensitive time determines this first sensitive time.

10. image sensing method as claimed in claim 7 is characterized in that, more comprises the step that a light source is provided.

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