# US 6,720,938 B2 · Head-up display on a vehicle, with controlled brightness of warning light > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,720,938 B2 - Document ID: US6720938B2 - Status: Granted - Kind: B2 - Application number: 09/850,243 - Filed: 2001-05-07 - Published: 2001-11-15 - Granted: 2004-04-13 - Earliest claimed: 2000-05-09 - Assignees: Honda Giken Kogyo Kabushiki Kaisha - Inventors: Osamu Ohkawara; Masashi Satomura; Hiroshi Hattori; Takayuki Tsuji; Ken Asami - Web page: https://patentgrep.com/patent/US6720938B2 ## CPC - G09G 5/00: Control arrangements or circuits for visual indicators common to cathode-ray tube indicators and other visual indicators (image data processing or generation, in general G06T) - G01S 11/12: using electromagnetic waves other than radio waves - G09G 3/3406: {Control of illumination source (illumination devices structurally associated with liquid crystal cells G02F1/1336)} - G09G 2320/0606: Manual adjustment - G09G 2320/062: Adjustment of illumination source parameters - G09G 2320/0626: for control of overall brightness - G09G 2320/0633: by amplitude modulation of the brightness of the illumination source - G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00) - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES ## Abstract A head-up display on a vehicle, which calls the attention of the driver or passenger to a dangerous object and makes the driver or passenger reliably recognize a communicated alarm, comprises: an image display device for displaying an image taken by a camera; a detecting device for detecting a target object; a switching device for manually switching between a display state and a warm-up state; and a warning device for outputting a control signal based on the detected result, thereby making the image display device display the image. The brightness for displaying the image according to the control signal is higher than the brightness for displaying the image according to a manual operation of the switching device. ## Claims ### Claim 1 A head-up display on a vehicle, comprising: an image display device for displaying an image taken by a camera built into the vehicle such that the image is visible to a vehicle occupant looking toward a windscreen of the vehicle; a detecting device for detecting a target object in the vicinity of the vehicle; a switching device for manually switching between a display state in which the image is displayed by the image display device and a warm-up state in which the image is invisible; and a warning device for outputting a control signal based on a result detected by the detecting device, thereby making the image display device display the image, wherein the brightness employed by the image display device for displaying the image according to the control signal is higher than the brightness employed by the image display device for displaying the image according to a manual operation of the switching device; in the warm-up state, the image is displayed with a brightness by which the image is invisible to the driver or passenger of the vehicle; and when a predetermined time has elapsed after the image display device starts to display the image, the display state is shifted to the warm-up state. ### Claim 2 (depends on 1) A head-up display as claimed in claim 1, wherein when the image display device displays the image according to the control signal from the warning device, the image display device reduces the brightness after a predetermined time from the starting of the display. ### Claim 3 (depends on 1) A head-up display as claimed in claim 1, wherein the image display device has a light source for changing the brightness of the displayed image according to an applied voltage supplied to the light source; and when the image display device is commanded to display the image by a manual operation of the switching device or the control signal output from the warning device, the image display device supplies the maximum applied voltage to be applied to the light source for a predetermined time. ### Claim 4 (depends on 1) A head-up display as claimed in claim 1, wherein the detecting device outputs an alarm signal when detecting a target object in the vicinity of the vehicle; and image display device displays a predetermined still image according to the alarm signal output from the detecting device, and wherein the brightness employed by the image display device for displaying the still image according to the alarm signal is higher than the brightness employed by the image display device for displaying the image according to a manual operation of the switching device. ### Claim 5 (depends on 4) A head-up display as claimed in claim 4, wherein when the image display device displays the still image according to the alarm signal from the detecting device, the image display device reduces the brightness after a predetermined time from the starting of the display. ### Claim 6 (depends on 4) A head-up display as claimed in claim 4, wherein when both the control signal from the warning device and the alarm signal from the detecting device are output, the image display device displays the image taken by the camera and the still image which are overlapped. ### Claim 7 A head-up display on a vehicle, comprising: an image display device for displaying an image taken by a camera built into the vehicle such that the image is visible to a vehicle occupant looking toward a windscreen of the vehicle; a detecting device for detecting a target object in the vicinity of the vehicle; a switching device for manually switching between a display state in which the image is displayed by the image display device and a warm-up state in which the image is invisible; and a warning device for outputting a control signal based on a result detected by the detecting device, thereby making the image display device display the image; wherein the brightness employed by the image display device for displaying the image according to the control signal is higher than the brightness employed by the image display device for displaying the image according to a manual operation of the switching device; the image display device has a light source for changing the brightness of the displayed image according to an applied voltage supplied to the light source; when the image display device is commanded to display the image by a manual operation of the switching device or the control signal output from the warning device, the image display device supplies the maximum applied voltage to be applied to the light source for a predetermined time; and after the image display device supplies the maximum applied voltage to be applied to the light source for the predetermined time, the image display device reduces the voltage supplied to the light source to either a level corresponding to a high brightness image display when the image display device is commanded to display the image by the control signal output from the warning device or a level corresponding to a lesser brightness image display when the image display device is commanded to display the image by the manual operation of the switching device.