Patent Application
20090278765
Embodiments of the subject matter described herein relate generally to head up display (HUD) systems. More particularly, embodiments of the subject matter relate to HUD systems used in vehicles.
A number of vehicles are now available with HUD systems that are designed to project a virtual display of instrumentation data to drivers. For example, HUD systems can be used to generate a virtual speedometer, a virtual tachometer, and/or other virtual instruments for the vehicle. A typical onboard HUD system generates a source image that is reflected using one or more mirrors and, ultimately, the windshield of the vehicle. The driver perceives the image reflected from the windshield. For example,
A method for processing images in a HUD system of a vehicle is provided. The method may begin by providing a plurality of image compensation templates, where each template can be applied to alter display characteristics of image data. The method involves selecting one of the plurality of image compensation templates for use as a compensating template, adjusting original image data in accordance with the compensating template to obtain adjusted image data, and rendering the adjusted image data on a HUD display source.
A HUD system for a vehicle having a windshield is also provided. The HUD system includes a HUD display source, a mirror configured to reflect images that originate from the HUD display source, and a motor coupled to the mirror. The motor adjusts the position of the mirror such that the mirror reflects images toward a controlled image target area of the windshield. The motor has related motor position data that is indicative of the position of the mirror. The HUD system also includes an image processor coupled to the HUD display source. The image processor is configured to transform original image data into adjusted image data in a variable manner that is influenced by the motor position data. The HUD display source is configured to render the adjusted image data.
A method for processing images in a HUD system of a vehicle having a windshield is also provided. The method involves selecting a controlled image target area from a plurality of different image target areas of the windshield, selecting, based upon the controlled image target area, one of a plurality of different position-dependent image transformation settings for use as a current transformation setting, and transforming original image data in accordance with the current transformation setting to obtain transformed image data. The method then renders the transformed image data on a HUD display source.
This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.
A more complete understanding of the subject matter may be derived by referring to the detailed description and claims when considered in conjunction with the following figures, wherein like reference numbers refer to similar elements throughout the figures.
The following detailed description is merely illustrative in nature and is not intended to limit the embodiments of the subject matter or the application and uses of such embodiments. As used herein, the word “exemplary” means “serving as an example, instance, or illustration.” Any implementation described herein as exemplary is not necessarily to be construed as preferred or advantageous over other implementations. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description.
Techniques and technologies may be described herein in terms of functional and/or logical block components, and with reference to symbolic representations of operations, processing tasks, and functions that may be performed by various computing components or devices. It should be appreciated that the various block components shown in the figures may be realized by any number of hardware, software, and/or firmware components configured to perform the specified functions. For example, an embodiment of a system or a component may employ various integrated circuit components, e.g., memory elements, digital signal processing elements, logic elements, look-up tables, or the like, which may carry out a variety of functions under the control of one or more microprocessors or other control devices.
For the sake of brevity, conventional techniques related to HUD systems, digital image processing, computer graphics, and other functional aspects of the systems (and the individual operating components of the systems) may not be described in detail herein. Furthermore, the connecting lines shown in the various figures contained herein are intended to represent exemplary functional relationships and/or physical couplings between the various elements. It should be noted that many alternative or additional functional relationships or physical connections may be present in an embodiment of the subject matter.
An onboard HUD system for a vehicle is described herein. Such a HUD system utilizes optics and image processing to compensate for distortion effects introduced by a given windshield shape. A mirror in the HUD system is adjusted to move the HUD image to accommodate the particular eye position of the driver. Movement of the HUD image results in a change in the image target area of the windshield from which the HUD image is reflected. The shape of most vehicle windshields varies throughout the HUD image adjustment range and, consequently, the shape of the reflected HUD image may distort when the image target area is moved. This creates an effect akin to a funhouse mirror, where the image perceived by the user appears altered, bent, distorted, or deformed.
The HUD system described herein adjusts its optics and image processing according to user-initiated instructions that control the position of the HUD image. The image target area of the windshield is correlated to the electronic adjustment of the HUD system mirror (or mirrors). The corresponding distortion pattern for each particular image target area of the windshield is utilized to pre-distort or compensate the HUD image in an appropriate manner. Thus, the original image rendered on the HUD display source is pre-warped in anticipation of the distortion to be introduced by the given image target area of the windshield. As a result, the actual HUD image as viewed by the driver will appear clear, crisp, and undistorted.
Image processor 202 may be implemented or performed with a general purpose processor, a content addressable memory, a digital signal processor, an application specific integrated circuit, a field programmable gate array, any suitable programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination designed to perform the functions described here. A processor may be realized as a microprocessor, a controller, a microcontroller, or a state machine. Moreover, a processor may be implemented as a combination of computing devices, e.g., a combination of a digital signal processor and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a digital signal processor core, or any other such configuration.
Memory 212 is utilized as a memory element for image processor 202. Memory 212 may be realized as RAM memory, flash memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, a CDROM, or any other form of storage medium known in the art. In this regard, memory 212 can be coupled to image processor 202 such that image processor 202 can read information from, and write information to, memory 212. In the alternative, memory 212 may be integral to image processor 202. As an example, image processor 202 and memory 212 may reside in an ASIC. As described in more detail below, memory 212 can be utilized to store and maintain data associated with, or representative of, different image processing schemes, including, without limitation: image compensation templates; image distortion rules; image transformation settings; image deformation guidelines; image adjustment algorithms; or the like.
Image processor 202 is suitably configured to perform the various routines, tasks, processes, and functions that support the operation of HUD system 200 as described in more detail herein. For example, image processor 202 is preferably configured to transform original (i.e., uncorrected) image data 214 into adjusted image data in a variable manner that is influenced by one or more adjustable characteristics or parameters of HUD system 200. These adjustable characteristics or parameters may include, without limitation: position data associated with a position of motor 208; mirror position commands that control the positioning of adjustable mirror 206; a windshield image target area utilized for the HUD image; a user-initiated request to control the position of adjustable mirror 206; seat position data associated with the adjustment of the driver's seat; and the like. As depicted in
HUD display source 204 is suitably configured render and display source images that are reflected for use as the actual HUD images. In this regard, HUD display source 204 can generate source images having any appropriate content, including, without limitation: the vehicle speed; vehicle warning indicators; cruise control status information; and/or clock information. In practice, image processor 202 may include or cooperate with an appropriate display driver (not shown), which controls and manages the rendering of graphical information on HUD display source 204. Notably, the specific configuration, operating characteristics, size, resolution, and functionality of HUD display source 204 can vary depending upon the practical implementation of HUD system 200. For example, HUD display source 204 may be realized using LCD, plasma display, LED, OLED, or other display technologies. In preferred embodiments, HUD display source 204 is of relatively high quality and high resolution, which is desirable to facilitate the various image processing techniques described here. In practice, HUD display source 204 may have a horizontal resolution within the range of about 300-800 pixels, and a vertical resolution within the range of about 150-600 pixels. In accordance with one embodiment that utilizes 5× magnification, HUD display source 204 has a resolution of 480 (horizontal) by 240 (vertical) pixels. In accordance with another embodiment that utilizes 7× magnification, HUD display source 204 has a 3:1 widescreen format that employs a resolution of 640 (horizontal) by 212 (vertical) pixels.
The dashed line in
As mentioned above, HUD system 200 can electronically control the rotatable position of adjustable mirror 206. In this regard, HUD system 200 includes motor 208, which is coupled to adjustable mirror 206 such that motor 208 can rotate adjustable mirror 206 as needed. Accordingly, motor 208 adjusts the position of adjustable mirror 206 such that adjustable mirror 206 reflects images toward a controlled image target area of the windshield (as described in more detail below). In other words, rotation of adjustable mirror 206 results in a corresponding shift in the image target area at which the reflected image is directed. In certain embodiments, motor 208 is realized as an electronic stepper motor that rotates adjustable mirror 206 in a stepwise manner. Thus, a given position or state of motor 208 corresponds to a respective position or state of adjustable mirror 206. In this regard, motor 208 may generate or include associated motor position data that is indicative of the position of adjustable mirror 206. Moreover, motor 208 may generate or include an associated mirror position command that controls the position of adjustable mirror 206 relative to the windshield. Depending upon the particular embodiment of HUD system 200, image processor 202 may process the motor position data and/or the mirror position command to determine how best to generate the adjusted image data.
This embodiment of HUD system 200 uses HUD image position control element 210 to initiate adjustment of the HUD image as perceived by the driver. HUD image position control element 210 may be realized as one or more switches, one or more buttons, one or more knobs, and/or any suitable user interface element that is configured to obtain user-initiated commands or requests. In practice, HUD image position control element 210 may employ physical devices, software driven display menus, a touch screen, a touchpad, a voice-activated control element, or the like. In preferred embodiments, HUD image position control element 210 is manipulated, engaged, or otherwise activated to control the position of motor 208, which in turn controls the position of adjustable mirror 206, which in turn controls the image target area on the windshield.
Image processor 202 applies the different image compensation templates, rules, settings, guidelines, and/or protocols to adjust the original image data 214 as needed such that the resulting HUD image as perceived by the driver is relatively distortion free, clear, and crisp, with little or no cropping, vignetting, or other unwanted visual artifacts. To accomplish this, image processor 202 applies a position-dependent image adjustment scheme to original image data 214, where the given image adjustment scheme corresponds to the current position of adjustable mirror 206 and, in turn, the current image target area on the windshield. For example, more image compensation is applied when the image target area corresponds to a highly contoured section of the windshield, and less image compensation is applied when the image target area corresponds to a less contoured section of the windshield.
In the preferred embodiment, HUD system 200 utilizes a plurality of predetermined image adjustment schemes, where the set of schemes is calibrated for the particular size, shape, and contour of the windshield. Accordingly, a different set of image compensation schemes can be utilized for each model of vehicle (assuming that each model uses the same production windshield). The calibration procedure for a given windshield may contemplate and identify different possible image target areas on the windshield, and then analyze the shape, contour, and optical characteristics of the image target areas. Then, for each image target area, the reflective properties are determined such that any distortion or deformation pattern can be identified and quantified. Thereafter, a corresponding image compensation template, algorithm, or rule is created for each image target area, where an image compensation template, algorithm, or rule represents the inverse of the distortion/deformation characteristic of the respective image target area. In other words, an image compensation rule results in pre-distortion or pre-deformation of original image data 214 in a manner that depends upon the respective image target area and, consequently, the respective position of adjustable mirror 206.
As mentioned previously, HUD system 200 may carry out image adjustment schemes using different techniques. For example, an image adjustment scheme may be realized using templates, rules, settings, algorithms, guidelines, protocols, or routines to perform image compensation, image distortion, or image transformation. Notably, each image adjustment scheme is applicable to alter the display characteristics of original image data 214. HUD system 200 may leverage any suitable image processing techniques and technologies to implement its image adjustment schemes. In this regard, HUD system 200 may utilize existing, known, or conventional image processing techniques and routines.
An “image compensation template” refers to a conceptual processing overlay that defines how the graphical elements of original image data 214 will be altered within the area of HUD display source 204. Conceptually, an image compensation template is akin to a distorting lens or filter that, when placed over original image data 214, results in the desired adjusted image data. As used herein, an “image distortion rule” is a rule (or set of rules) that governs how original image data 214 is modified to create the adjusted image data. Alternatively or additionally, HUD system 200 might utilize different image transformation settings, where an “image transformation setting” represents one or more configurable parameters, variables, options, or characteristics that influence the manner in which image processor 202 alters original image data 214 into the respective adjusted image data. For example, an image transformation setting may dictate parameters such as, without limitation: stretching, bending, rotation, shrinking, translation, swirling, or the like.
Referring to
In
In contrast,
In
A HUD system as described herein can be suitably configured to produce clear and undistorted HUD images, regardless of the HUD image position setting. In this regard,
HUD image adjustment process 400 may begin with (or be initialized by) providing, storing, and maintaining a plurality of calibrated image processing schemes for the HUD system (task 402). Depending upon the particular embodiment, task 402 may be associated with different image adjustment templates, rules, settings, algorithms, guidelines, protocols, or the like, as mentioned above with reference to
During operation of the vehicle, process 400 may obtain a user-initiated request to control and/or select certain HUD system image characteristics (task 404). For example, the user-initiated request may be: a command to adjust the height of the HUD image; a request to control the position of an adjustable mirror of the HUD system; a request to control the position of the motor used to adjust the mirror; a mirror position command; a request to select a controlled image target area from a plurality of different image target areas of the windshield; or the like. For this exemplary embodiment, task 404 is performed when the driver engages a user interface element that controls the displayed position of the HUD image. In turn, this causes the mirror positioning motor to adjust the position (tilt) of the adjustable mirror, using an appropriate mirror position command (task 406). In addition, this causes the image processor to obtain motor position data (task 408) from the motor.
Process 400 may then utilize the mirror position command and/or the motor position data to influence or determine its selection of a particular image adjustment scheme that best matches the current height of the HUD image (task 410). For example, if the HUD image is relatively high on the windshield, then task 410 may select image compensation template A. On the other hand, if the HUD image is relatively low on the windshield, then task 410 may select image compensation template B. Again, task 410 may select a designated image compensation template, a designated image distortion rule, or a designated image transformation setting, and the selection performed during task 410 may be governed by the mirror position command, the motor position data, and/or the particular image target area that corresponds to the user-controlled HUD image height.
During operation, the HUD system generates the original image data (task 412), which represents the intended HUD display content. As explained above, this original image data need not actually be rendered or displayed. Rather, process 400 adjusts, transforms, pre-corrects, distorts, alters, or otherwise modifies the original image data (task 414), in accordance with the image adjustment scheme selected during task 410. The data processing that occurs during task 414 results in adjusted, transformed, altered, or modified image data that is derived from the original image data. The adjusted image data is generated in a suitable manner that compensates for the curvature of the windshield at the controlled image target area (which, in turn, is dependent upon the adjusted height of the HUD display).
In an exemplary embodiment, the adjusted image data is formatted such that the HUD display source can render it in an appropriate manner in accordance with its native capabilities, settings, and configuration. Accordingly, process 400 renders the adjusted image data on the HUD display source to generate a corresponding source image for the HUD system (task 416). The actual source image displayed at the HUD display source will appear distorted, warped, bent, or misshapen in most circumstances, and the particular distortion characteristics of the source image will depend upon the specific image target area. In this regard,
The embodiment depicted in
Referring again to
After task 420, process 400 may exit or it may be re-entered at task 412 as needed to update the HUD system with new original image data. In other words, tasks 412, 414, 416, 418, and 420 can be repeated to continuously or periodically update the HUD image as long as the position of the HUD image remains unchanged. If, however, the position of the HUD image is adjusted (with a corresponding adjustment of the controlled image target area on the windshield), then process 400 may be repeated or re-entered at an appropriate point, e.g., at task 404 or task 406.
While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or embodiments described herein are not intended to limit the scope, applicability, or configuration of the claimed subject matter in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the described embodiment or embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope defined by the claims, which includes known equivalents and foreseeable equivalents at the time of filing this patent application.
