Vehicle display device

Abstract

To provide a vehicular display device which has improved resistance against abnormality in a power source.SOLUTION: A vehicular display device is a head-up display 1 mounted in a vehicle C for displaying vehicle information and comprises: a display Di for displaying vehicle information; a processor 10 for controlling the display Di; a first power supply V1 which transforms a power source voltage VB externally applied to a first voltage V1 and then supply power to the processor 10; a second power supply 12 which transforms the power source voltage VB to a second voltage V2; and a voltage determination part which operates on the basis of the second voltage V2 and puts the first power supply 11 into a normal operation when the first voltage V1 is less than a first threshold value voltage and stops the first power supply 11 when the first voltage V1 is equal to or greater than the first threshold value voltage.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a display device for a vehicle. [Background technology]

[0002] As a conventional vehicle display device, for example, the configuration described in Patent Document 1 is known. The vehicle display device disclosed in Patent Document 1 is a head-up display (1) that operates by receiving power from a battery (45). The power supply unit (22) is a transformer that transforms the voltage applied from the battery (45) to the head-up display (1) and then supplies the power to each component that constitutes the head-up display (1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-144743 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the configuration described in Patent Document 1, if an abnormality occurs in the external power supply that applies voltage to the head-up display, the abnormal voltage may be applied to each component that makes up the head-up display, which may lead to malfunction of the device.

[0005] SUMMARY OF THE PRESENT EMBODIMENT In view of the above, an object of the present invention is to provide a vehicle display device having improved resistance to power supply abnormalities. [Means for solving the problem]

[0006] In order to achieve the above object, the present invention provides a display device for a vehicle, comprising: A vehicle display device that is mounted on a vehicle and displays vehicle information, a display for displaying the vehicle information; a processor for controlling the display; a first power supply that transforms an externally applied power supply voltage into a first voltage and supplies power to the processor; a second power source that transforms the power source voltage to a second voltage; Operates based on the second voltage; operating the first power supply normally when the first voltage is less than a first threshold voltage; a voltage determination unit that stops the first power supply when the first voltage is equal to or higher than a first threshold voltage; Equipped with The processor outputs a voltage abnormality occurrence signal to an external device when the first voltage is lower than the first threshold voltage and equal to or higher than a second threshold voltage. R 。 [Brief description of the drawings]

[0007] [Figure 1] 1 is a diagram showing a configuration of a head-up display 1 according to an embodiment of the present invention. [Diagram 2] Block diagram showing the configuration of HUD 1 and meter 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] As an example of a vehicle display device according to the present disclosure, a head-up display (HUD) 1 mounted on a vehicle C will be described below as an embodiment and a modified example with reference to the accompanying drawings in the following order. Note that directions F, B, L, R, U, and D shown in the drawings correspond to the front, rear, left, right, up, and down directions of the vehicle C, respectively. The left-right direction may be referred to as direction X, the up-down direction as direction Y, and the front-rear direction as direction Z.

[0009] [First embodiment] 1-1. Description of the configuration 1-2. Description of behavior [Variations]

[0010] [First embodiment] <1-1. Description of the configuration> As shown in FIG. 1, a head-up display (HUD) 2 can be mounted below a windshield WS provided on a vehicle C.

[0011] The HUD1 projects a virtual image V by projecting display light Li representing vehicle information onto a windshield WS (reflective and transmissive material) that has a free-form curved surface shape that is inclined so that the front end of the vehicle is lower. The HUD1 emits the display light Li diagonally upward toward the rear of the vehicle. The display light Li emitted to the HUD1 is reflected by the windshield WS. A user (e.g., a passenger of the vehicle C) who views the display light Li reflected by the windshield WS at a viewpoint EP can view the projected virtual image V as a display image floating behind the windshield WS.

[0012] The virtual image V displays vehicle information that is highly necessary to alert the occupant (user), such as vehicle information such as speed and engine RPM, route guidance displays such as turn-by-turn and maps, and warning displays such as blind spot monitors and speed limit exceeding warnings. This provides a driving environment with reduced viewpoint movement and eye focal length adjustment. The virtual image V includes characters and icons indicating this information as well as a background portion, and in a planar view from the occupant, this has, for example, a rectangular shape.

[0013] The HUD1 mainly operates in two modes. One is a display mode in which the HUD1 projects the display light Li onto the windshield WS, as shown in FIG. 1, so that the virtual image V can be seen from the viewpoint EP. The other is a pause mode (parking mode) in which the HUD1 does not project the display light Li onto the windshield WS, so that the virtual image V cannot be seen from the viewpoint EP. The HUD1 in the parking mode, in which the display light Li is not projected onto the windshield WS, is located in a position where it does not reflect the external light (mainly sunlight) incident on the HUD1 from the windshield WS direction to the direction in which the display light Li is incident (the direction in which the display unit is optically located) based on the principle of reverse light propagation. This prevents the display unit from being illuminated by external light and becoming hot when the HUD1, which is considered to be in a state in which the vehicle C is stopped, is in the parking mode. To switch between these modes, the HUD 1 rotates the reflecting portion 30 using a configuration that will be described later.

[0014] In the display mode, the HUD1 can change the optical path of the display light Li by a configuration described later in order to adjust the height of the viewpoint EP at which the virtual image V can be viewed. In the present disclosure, as shown in the drawings, the optical path can be changed to three types: a shorter display light Ls, a center display light Lc, and a toler display light Lt. In the display mode, the shorter display light Ls is projected by the HUD1 onto a relatively lower part of the windshield WS, and a virtual image V is displayed. In the toler display light Lt, the HUD1 projects the display light Li onto a relatively upper part of the windshield WS, and a virtual image V is displayed. In the center display light Lc, the display light passes between the two display optical paths described above, and a virtual image V is displayed. The HUD 1 includes a display unit Di and a reflector Mi.

[0015] The display unit Di, which is an example of a display, is a member that emits display light Li. In the present disclosure, the display light Li is emitted in a direction F. As a member that emits the display light Li, for example, a configuration using a TFT liquid crystal module, a configuration using an organic EL, a projector using a DMD (Digital Micro-mirror Device), and the like can be applied. In a configuration using a TFT liquid crystal module, for example, the display unit Di is configured to have a backlight unit and a liquid crystal display element that are connected to a control unit in a fixed state, and the liquid crystal display element that displays information under the control of the control unit is illuminated by illumination light emitted from a backlight unit whose blinking is controlled under the control of the control unit to emit the display light Li. However, it goes without saying that the effect of the configuration of the present disclosure can be achieved as long as the configuration can emit display light other than the exemplified ones.

[0016] The reflecting portion Mi reflects the display light Li. The reflecting portion Mi is, for example, a mirror whose surface that reflects the display light Li has a concave free-form shape, and the mirror surface is formed by a method such as vapor deposition or sputtering. The reflecting portion Mi reflects the display light Li while expanding it. A hard synthetic resin or inorganic glass can be applied to the base material of the reflecting portion Mi. In addition, it is desirable that the reflecting portion Mi has a shape that offsets distortion of the virtual image V that is expected to occur on the windshield WS due to the free-form shape.

[0017] The reflecting portion Mi may include a holder. The holder holds the reflecting portion Mi rotatably about a rotation axis A. The holder may be made of a hard metal such as magnesium or iron, or a hard synthetic resin such as ABS resin.

[0018] The configuration of the HUD 1, meter 2, and battery 3 mounted on the vehicle C is shown in FIG. 2. The magnitude relationships among the three voltages mentioned in the description are as follows. The voltage values ​​are merely examples. Typical value of first voltage = 3.3V < second threshold voltage = 3.5V < first threshold voltage = 3.8V

[0019] The HUD 1 further includes a microcomputer (an example of a control unit) 10, a first power supply 11, a second power supply 12, and a voltage determination unit 13.

[0020] The microcomputer 10, which is an example of a processor, can be a microcomputer equipped with a memory unit such as a ROM or RAM (not shown) used for storing a predetermined program and various data, a memory area during calculation, a CPU for performing calculations according to the predetermined program, and an input / output interface, etc. The control unit is electrically connected to the display unit Di, the power unit, and electronic devices outside the HUD 1. Based on vehicle information received from on-board devices outside the HUD 1, the control unit generates an image to be displayed on the display unit Di, controls the display of the display unit Di, controls the illuminance of the display unit Di, and controls the rotation of the reflector Mi.

[0021] The microcomputer 10 is supplied with power by applying a first voltage V1 from a first power supply 11. The microcomputer 10 can determine whether the first voltage V1 is equal to or greater than the second threshold voltage based on the voltage applied to the power supply monitor pin 10a. For example, in the present disclosure, the second voltage V2 applied to the power supply monitor pin 10a is typically 5V, and the first voltage V1 is typically 3.3V. The microcomputer 10 can determine whether the first voltage V1 is equal to or greater than the second threshold voltage based on the 5V potential of the second voltage V2.

[0022] The second threshold voltage is a reference voltage that, when the microcontroller 10 is set to a value greater than the recommended operating range voltage (e.g., 3.3 V±0.2 V) and is less than a voltage that may cause an internal abnormality (first threshold voltage, absolute maximum rated voltage, e.g., 3.8 V), notifies the user that an abnormality has occurred in the first voltage V1 while the microcontroller 10 is operating.

[0023] The microcomputer 10 is electrically connected to a microcomputer 20 mounted on a meter 2 described later. The microcomputer 10 is capable of communicating various electrical signals with the microcomputer 20, and is capable of transmitting, for example, a voltage abnormality occurrence signal ER that notifies of an abnormality in the first voltage V1 (above the second threshold voltage).

[0024] The first power supply 11 and the second power supply 12 are transformers that transform a power supply voltage VB applied from an external source (such as a battery 3). The first power supply 11 applies a first voltage V1 after the transformation to the microcomputer 10 and the voltage determination unit 13 to supply power. The second power supply 12 applies a second voltage V2 after the transformation to the voltage determination unit 13 and the power supply monitor pin 10a of the microcomputer 10 to supply power.

[0025] Various types of transformers can be used for the first power source 11 and the second power source 12, and for example, a linear regulator, a DC / DC converter such as a switching regulator, or the like can be used.

[0026] The voltage determination unit 13 determines whether the potential of the first voltage V1 is equal to or greater than a threshold value or less than a threshold value. Specifically, when the first voltage V1 is equal to or greater than the first threshold voltage, the voltage determination unit 13 turns the enable signal EN to an OFF state and stops the operation of the first power supply 11. When the first voltage V1 is less than the first threshold voltage, the voltage determination unit 13 turns the enable signal EN to an ON state and causes the first power supply 11 to operate normally.

[0027] The voltage determination unit 13 may be configured to determine whether the first voltage V1 is large or small, and may be implemented by, for example, a reset IC or a comparator. The voltage determination unit 13 operates when the second voltage V2 is applied and power is supplied to it. Since the voltage determination unit 13 is an element that monitors the first voltage V1, it is desirable for the voltage determination unit 13 to be provided via a power source separate from the first voltage V1.

[0028] The meter 2 is a display device that displays vehicle information to a user. For example, it can be configured as an electronic display capable of displaying images using TFT or organic EL, a pointer-type instrument configured with a pointer and an index, a warning light, or the like. The meter 2 includes a microcomputer 20 and a power supply 21. The microcomputer 20 can be configured similarly to the microcomputer 10. The power supply 21 is electrically connected to the battery 3, which is an external power supply, and the HUD 1, and supplies power supplied from the battery 3 to the HUD 1 and the microcomputer 20. The power supply 21 outputs the voltage (e.g., 12 V) output by the battery 3 to the HUD 1 as the power supply voltage VB as it is. The power supply 21 applies a voltage (e.g., 3.3 V) obtained by stepping down the power supply voltage VB to the microcomputer 20. When the voltage abnormality occurrence signal ER is input from the microcomputer 20, the meter 2 notifies the user using a warning light or an electronic display.

[0029] The battery 3 is a power supply device constituted by a secondary battery, etc. For example, a 12V power supply constituted by a lead storage battery can be applied as the battery 3.

[0030] <1-2. Description of behavior> HUD1 operates based on the following behavior:

[0031] (When the first voltage is within the recommended operating range voltage) The HUD 1 performs normal operation and displays vehicle information to the user.

[0032] (When the first voltage is equal to or greater than the first threshold voltage) When an abnormality occurs in the first power supply 11, the first voltage may become equal to or higher than the first threshold voltage. In this case, a voltage equal to or higher than the absolute maximum rated voltage is applied to the microcomputer 10, exposing the microcomputer 10 to a state in which the inside of the microcomputer 10 may be destroyed. In such a case, it is desirable for the microcomputer 10 to be shut down immediately before transmitting an error signal to the outside.

[0033] Therefore, in this embodiment, whether the first voltage V1 is equal to or higher than the first threshold voltage is determined by the voltage determination unit 13, not the microcomputer 10. When the voltage determination unit 13 determines that the first voltage V1 is equal to or higher than the first threshold voltage, it turns off the enable signal EN and stops the operation of the first power supply 11.

[0034] This allows the state in which a voltage exceeding the absolute maximum rated voltage is applied to the microcomputer 10 to be quickly eliminated, resulting in a vehicle display device with improved resistance to power supply abnormalities. As a specific failure case, when a voltage exceeding the absolute maximum rated voltage is applied, the inside of the microcomputer 10 is destroyed in some way, and the display of the display unit Di is fixed at a white image and maximum light amount. In this case, the virtual image V obstructs the user's field of vision. With the configuration of the present disclosure, even if the inside of the microcomputer 10 is destroyed, the operation of the entire HUD 1 can be stopped by stopping the operation of the first power supply 11. Furthermore, with this configuration, the microcomputer 10 can be shut down before the microcomputer 10 enters a loop due to some kind of failure and reaches a state in which the operation of the microcomputer 10 cannot be changed.

[0035] (When the first voltage is equal to or greater than the second threshold voltage and less than the first threshold voltage) When an abnormality occurs in the first power supply 11, the first voltage V1 may be equal to or higher than the second threshold voltage and lower than the first threshold voltage. In other words, the first voltage V1 does not exceed the absolute maximum rated voltage, but deviates from the recommended operating range voltage. In this case, the microcomputer 10 does not need to immediately stop operation, but it is desirable for the microcomputer 10 to take action such as notifying the user of the abnormality.

[0036] As a method for notifying the user of an abnormality, for example, the microcontroller 10 outputs a voltage abnormality signal ER to the microcontroller 20 of the meter 2, and in response, the microcontroller 20 utilizes the display function of the meter 2 to notify the user that an abnormality in the equipment (abnormality in the first voltage V1) has occurred.

[0037] This configuration prevents the device from being destroyed by a voltage abnormality, while allowing the device to continue to operate and notify the user of a minor voltage abnormality, resulting in a vehicle display device with improved resistance to power abnormalities.

[0038] [Variations] Although the vehicle display device of the present invention has been described using the above-mentioned embodiment as an example, the present invention is not limited to this, and it goes without saying that various improvements and changes to the display are possible in other configurations as well, without departing from the gist of the present invention.

[0039] For example, the voltage determination unit 13 is shown to be a reset IC, but is not limited to this configuration. For example, as described above, any element whose output changes electrically depending on the magnitude of the voltage, such as a comparator, may be used. However, in the present disclosure, it is preferable to use a reset IC because it is inexpensive and has a simple configuration. [Explanation of symbols]

[0040] C Vehicle WS Windshield EP Perspective V Virtual Image A Rotation Axis Di display section (example of display) Mi reflector Li,Lt,Lc,Ls Display light VB Battery voltage V1 First voltage V2 Second voltage 1. Head-up display (HUD, an example of a vehicle display device) 10 Microcomputer (an example of a processor) 11 1st power supply 12 2nd power supply 13 Voltage judgment section 2 Meter 20 Microcomputer 21 Power supply

Claims

1. A vehicle display device that is mounted on a vehicle and displays vehicle information, a display for displaying the vehicle information; a processor for controlling the display; a first power supply that transforms an externally applied power supply voltage into a first voltage and supplies power to the processor; a second power source that transforms the power source voltage to a second voltage; Operates based on the second voltage; operating the first power supply normally when the first voltage is less than a first threshold voltage; a voltage determination unit that stops the first power supply when the first voltage is equal to or higher than a first threshold voltage; Equipped with The processor outputs a voltage abnormality occurrence signal to an external device when the first voltage is lower than the first threshold voltage and equal to or higher than a second threshold voltage. Vehicle display device.

2. the vehicle display device is a head-up display, The device is a meter The display device for a vehicle according to claim 1 .

3. The voltage determination unit is a reset IC. The display device for a vehicle according to claim 1 .

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