US 10,382,012 B2 · Navigation device and track smoothing method thereof

Abstract

A navigation device including a digital filter configured to smooth tracking is provided. The digital filter is configured to sequentially receive input data and output a tap sum, and calculate a quotient and a remainder by dividing an accumulation value with an average number, wherein the remainder is feedback to the tap sum for updating the accumulation value and the quotient is configured as output data.

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Claims12

Dependent claims

A navigation device, having a resolution indicated by dot per inch (DPI), and configured to detect motion and output smoothed displacement with respect to a working surface upon which the navigation device is operated, the navigation device comprising:

an image sensor configured to sense reflection light beams from the working surface and output input data which is not smoothed;
and
a processor comprising a digital filter which is coupled to the image sensor to receive the input data, the digital filter comprising:
a delay buffer comprising multiple taps configured to sequentially receive, at every clock cycle, a data series of the input data to be stored in the multiple taps in a first-in first-out operation from the image sensor, and output a tap sum, which is a sum of each data of the data series stored in the multiple taps;
an accumulation buffer configured to store, corresponding to the every clock cycle, an accumulation value;
a divider coupled to the accumulation buffer to receive the accumulation value, and configured to calculate, corresponding to the every clock cycle, a quotient and a remainder by dividing the accumulation value by an average number which is associated with a smoothing strength of the navigation device;
a remainder buffer coupled to the divider to receive, corresponding to the every clock cycle, the remainder, wherein the divider sets a calculated non-zero remainder to 0 when the quotient is 0, while the remainder is stored in the remainder buffer only when the quotient is larger than 0;
and
an adder coupled to the delay buffer, the remainder buffer and the accumulation buffer, and configured to add, corresponding to the every clock cycle, the tap sum and the remainder stored in the remainder buffer to generate the accumulation value when the quotient is larger than 0;
wherein the digital filter is configured to output, corresponding to the every clock cycle, the quotient as the smoothed displacement to control a cursor or a pointer on a display, and
when the resolution of the navigation device is changed from a first resolution to a second resolution higher than the first resolution, the average number is adjusted from a first number to a second number higher than the first number to increase the smoothing strength thereby reducing influence on the navigation device from noise or the working surface and increasing track smooth.

8 more elements

A track smoothing method of a navigation device, the navigation device detecting motion and outputting smoothed displacement with respect to a working surface upon which the navigation device is operated, the navigation device having a resolution indicated by dot per inch (DPI), and comprising an image sensor sensing reflection light beams from the working surface to output input data and a processor which comprises a digital filter with an average number which is associated with a smoothing strength of the navigation device, and coupled to the image sensor to receive the input data, the track smoothing method comprising:

receiving, at every clock cycle, a data series of the input data, which is not smoothed, from the image sensor to be sequentially stored in multiple taps of the digital filter in a first-in first-out operation;
calculating a tap sum of each data of the data series of the input data stored in every tap in the digital filter;
updating, corresponding to the every clock cycle, an accumulation value with the tap sum;
calculating, corresponding to the every clock cycle, a quotient and a remainder by dividing the accumulation value by the average number;
setting a calculated non-zero remainder to 0 when the quotient is equal to 0, while storing the remainder in a remainder buffer only when the quotient is larger than 0;
and
outputting, corresponding to the every clock cycle, the quotient as the smoothed displacement to control a cursor or a pointer on a display,
wherein when the resolution of the navigation device is changed from a first resolution to a second resolution higher than the first resolution, the average number is adjusted from a first number to a second number higher than the first number to increase the smoothing strength thereby reducing influence on the navigation device from noise or the working surface and increasing track smooth.

5 more elements

an image sensor configured to receive reflection light beams from the working surface and output input data which is not smoothed;
and
a processor comprising a digital filter which is coupled to the image sensor to receive, at every clock cycle, a data series of the input data, the digital filter comprising:
a divider configured to calculate, corresponding to the every clock cycle, a quotient and a remainder by dividing an accumulation value by an average number which is associated with a smoothing strength of the navigation device, wherein the divider sets a calculated non-zero remainder to 0 when the quotient is 0, while the remainder is stored in a remainder buffer only when the quotient is larger than 0;
and
an adder configured to
add, corresponding to the every clock cycle, next tap sum to the accumulation value stored in an accumulation buffer to update the accumulation value when the quotient is equal to 0, and
add, corresponding to the every clock cycle, the next tap sum and the remainder stored in the remainder buffer to generate a new accumulation value when the quotient is larger than 0,
wherein the next tap sum is a sum of each data of the data series of the input data stored in every of multiple taps in the digital filter received from the image sensor, and the data series of the input data are sequentially stored in the multiple taps in a first-in first-out operation, and
when the resolution of the navigation device is changed from a first resolution to a second resolution higher than the first resolution, the average number is adjusted from a first number to a second number higher than the first number to increase the smoothing strength thereby reducing influence on the navigation device from noise or the working surface and increasing track smooth,
wherein the digital filter is configured to output, corresponding to the every clock cycle, the quotient as the smoothed displacement to control a cursor or a pointer on a display.

8 more elements

Dependencies are inferred from the claim text.

Description4,136 words

Summary639 words

#1. Field of the Disclosure

#This disclosure generally relates to a navigation device and, more particularly, to a navigation device capable of performing track smoothing and a track smoothing method thereof.

#2. Description of the Related Art

Brief description of the drawings3 figures

#Other objects, advantages, and novel features of the present disclosure will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

#FIG. 1 is a schematic block diagram of a navigation device according to one embodiment of the present disclosure.

#FIG. 2 is an operational schematic diagram of a navigation device according to one embodiment of the present disclosure.

Detailed description3,410 words

#It should be noted that, wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

#Referring to FIG. 1, it is a schematic block diagram of a navigation device according to one embodiment of the present disclosure. The navigation device 1 of the present disclosure is, for example, operated on a working surface 5, and configured to detect the motion with respect to the working surface S and output smoothed displacement. It should be mentioned that although in FIG. 1 the navigation device 1 is shown to be operated on the working surface S, the present disclosure is not limited thereto. The navigation device 1 is also adaptable to handheld navigation devices such as a remote device, a pointing device or the like without particular limitations.

#The navigation device 1 includes a light source 20, an image sensor 30 and a digital filter 10, wherein the digital filter 10 is, for example, included in a processor. In some embodiments, the light source 20, the image sensor 30 and the digital filter 10 are all included in an image sensor package such as an image sensing chip, and the image sensor package is configured to output a smoothed track. In other embodiments, the light source 20 and the image sensor 30 are included in an image sensor package but the digital filter 10 is in an external processor, e.g. a central processing unit (CPU), a microcontroller (MCU) or the like outside of the image sensor package. It should be mentioned that when the navigation device 1 is adapted to a handheld navigation device, the light source 20 may not be implemented.

Facts

Application

14/605,007Filed 26 Jan 2015

Published

US 2016/0218697 A128 Jul 2016

Granted

13 Aug 2019

Term ends

17 Sep 2035

Estimated · how

20 years from earliest known nonprovisional domestic filing plus recorded patent term adjustment, including 234 days of adjustment. Maintenance-fee lapses, terminal disclaimers and statutory extensions have not been checked. The continuity chain may be incomplete; this is not an enforceability determination.

Classification3 codes

H03H 17/0248
Frequency selective networks: filters characterised by a particular frequency response or filtering method
H03H 17/026
Filters characterised by a particular frequency response or filtering method: averaging filters
H03H
Impedance networks

Timeline

26 Jan 2015Application filedUS 14/605,007
26 Jan 2015Assigned to Pixart Imaging (Penang) Sdn. Bhd.assignment of assignor's interest
28 Jul 2016PublishedUS 2016/0218697 A1
31 May 2019Assigned to Pixart Imaging Inc.assignment of assignor's interest
13 Aug 2019GrantedUS 10,382,012 B2
12 Oct 2026TodayWithin its term
17 Sep 2035Term endsEstimated, includes 234 days of adjustment

Navigation device and track smoothing method thereof

Life of this patent

Navigation device and track smoothing method thereof

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims12

Description4,136 words

Drawings

Classification3 codes

Life of this patent

Description4,136 words