JP5381798B2 - Vehicle display device - Google Patents

Description

  The present invention relates to a vehicle display device that displays a physical quantity to be displayed on a vehicle using a display.

  Conventionally, a meter image in which the number of dots in the setting direction from the reference coordinates changes according to the physical quantity to be displayed is used as a dot matrix type display as a meter image expressed by dots arranged in the setting direction from the reference coordinates. 2. Description of the Related Art A display device for a vehicle that is displayed is known (for example, see Patent Document 1).

  For such meter images, visibility is improved by masking with, for example, a frame-shaped mask image outside the range where the number of dots in the setting direction from the reference coordinates is the maximum number of dots according to the maximum physical quantity. Can be. Here, the meter image masked by the mask image is prepared by preparing a meter image in which the number of dots in the setting direction from the reference coordinates is the current number of dots corresponding to the current physical quantity, and masking the meter image of the current number of dots. This can be realized by generating a composite image in which images are superimposed.

JP 2009-18642 A

  As for the meter image as described above, the smaller the dot width corresponding to the same value of the physical quantity in the setting direction, the higher the resolution in the setting direction with respect to the physical quantity, but there is a difference in the number of dots in the setting direction. I have to prepare many images. For this reason, when priority is given to the resolution with respect to the physical quantity, it is necessary to store a large number of prepared meter images in a storage means such as a memory in advance, resulting in an increase in storage capacity. On the other hand, when priority is given to reducing the storage capacity, the resolution with respect to the physical quantity decreases, and the display accuracy of the physical quantity deteriorates.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a vehicular display device that achieves both reduction in image storage capacity and improvement in physical quantity display accuracy.

  The invention according to claim 1 is a meter image in which the number of dots in the setting direction from the reference coordinate is represented by dots arranged in the setting direction from the reference coordinate, and the setting direction from the reference coordinate. A display device for a vehicle that displays a composite image of a mask image that masks a meter image outside a range where the maximum number of dots according to the maximum physical quantity corresponds to the maximum physical quantity, on a dot matrix type display, The maximum meter image as the meter image in which the number of dots in the setting direction from the reference coordinates is the maximum number of dots, the mask image, and the storage means stored in advance, and the reference coordinates of the meter image to be displayed on the display As the number of dots in the setting direction, a calculation means for calculating the current number of dots according to the current physical quantity, and a reduction of the maximum meter image stored in the storage means Further, as a meter image in which the number of dots in the setting direction from the reference coordinates is a reduced dot number smaller than the maximum dot number, a reduction unit that generates a reduced meter image, a current dot number calculated by the calculation unit, and a reduction unit Determining means for determining the difference between the number of reduced dots of the reduced meter image generated by the step (1) and storing the reduced meter image generated by the reducing means as it is in the storage means when the determination is made by the determining means. The first composition unit that generates a composite image by compositing with the mask image, and the current dot number calculated by the calculation unit and the reduction generated by the reduction unit when a different determination is made by the determination unit Shift means for shifting the dot difference between the number of reduced dots of the meter image and the dot coordinates of the reduced meter image in a direction opposite to the setting direction; Reduced meter image which is shifted by preparative means, by combining the mask image stored in the storage means, characterized in that it comprises a second combining means for generating a composite image.

  Thus, according to the first aspect of the present invention, the maximum meter image having the maximum number of dots corresponding to the maximum physical quantity among the meter images in which the number of dots from the reference coordinates changes in accordance with the physical quantity to be displayed in the setting direction. Are stored in the storage means, and the remaining meter images can be prepared from the images in the storage. Specifically, in the invention described in claim 1, by reducing the maximum meter image stored in the storage unit, a reduction dot number smaller than the maximum dot number of the maximum meter image is secured in the setting direction from the reference coordinate. A meter image is generated. Here, generating all of the meter images that can be assumed in the range in which the number of dots in the setting direction from the reference coordinates is smaller than the maximum number of dots as a reduced meter image means that the reduction factor for the maximum meter image is limited. As a result, there are concerns about difficult situations.

  Therefore, in the first aspect of the invention, the current dot number calculated according to the current physical quantity as the dot number in the setting direction from the reference coordinates of the meter image to be displayed on the display, and the reduced dot of the reduced meter image Distinguish between numbers. As a result, when the current dot number and the reduced dot number are the same, the reduced meter image is directly combined with the mask image stored in the storage unit, and the combined image is displayed on the display. On the other hand, when the current dot number is different from the reduced dot number, the dot difference of those dot numbers and the dot coordinates of the reduced meter image are shifted in the direction opposite to the setting direction, A composite image with the mask image is displayed on the display. At this time, in the reduced meter image after the shift, the dot portion located in the direction opposite to the setting direction from the reference coordinate exists outside the range of the maximum number of dots from the reference coordinate in the setting direction. It is masked by the image. Therefore, in the displayed composite image, the reduced reduced meter image is not displayed for the dot portion that is out of the maximum dot number range by the dot difference between the current dot number and the reduced dot number, but fits within the maximum dot number range. The dot portion of the current number of dots will be displayed.

  As described above, according to either the reduced meter image obtained by reducing the maximum meter image starting from the reference coordinates or the reduced meter image obtained by coordinate shifting in addition to the reduction, the number of dots in the setting direction is within a range smaller than the maximum number of dots. All possible meter images can be displayed. Therefore, in this case, since the dot width corresponding to the same value of the display target physical quantity in the setting direction is one dot width, the resolution in the setting direction with respect to the physical quantity can be increased to the maximum. Moreover, the meter image stored in advance in the storage means can be limited to the maximum meter image having the maximum number of dots as described above. For these reasons, the invention described in claim 1 can achieve both a reduction in image storage capacity and an improvement in display accuracy of physical quantities.

  According to the second aspect of the present invention, when N is defined as an integer value smaller than the maximum number of dots and n is defined as a plurality of integer values of 1 to N, the number of reduced dots is a plurality of reduction ratios n / A plurality of values are set by integer approximation with respect to a value obtained by multiplying each of N and the maximum number of dots, and the reduction means is the current number of dots calculated by the calculation means among the plurality of reduction dots set. A reduced meter image is generated so that the number of reduced dots is as described above.

  Thus, according to the second aspect of the present invention, the current dot is selected from a plurality of reduction dot numbers set by integer approximation with respect to a value obtained by multiplying each of the plurality of reduction magnifications n / N and the maximum dot number. A reduced meter image is generated so that the number of reduced dots is greater than or equal to the number. Here, N is an integer value smaller than the maximum number of dots, and n is a plurality of integer values from 1 to N. Therefore, there is a restriction on the reduction ratio represented by n / N. . In this case, it is difficult to generate all of the meter images that can be assumed in a range where the number of dots in the setting direction is smaller than the maximum number of dots as a reduced meter image.

  However, in the invention described in claim 2, it is possible to generate not only a reduced meter image obtained by reducing the maximum meter image starting from the reference coordinates but also a reduced meter image obtained by shifting coordinates in addition to the reduction. All possible meter images can be displayed. Therefore, even under the restriction of the reduction ratio, it is possible to contribute to both the reduction of the image storage capacity and the improvement of the display accuracy of the physical quantity.

  Further, as a preferred aspect of the invention described in claim 2, according to the invention described in claim 3, the reduction means is equal to or more than the current number of dots calculated by the calculation means among a plurality of reduction dots set. A reduced meter image is generated so that the number of reduced dots that minimizes the dot difference from the current number of dots. According to this, when a dot difference occurs due to the difference between the reduced dot number and the current dot number, the dot coordinates of the reduced meter image are shifted by the dot difference minimized when the reduced meter image is generated. That's fine. Therefore, by using the reduced meter image that is coordinate-shifted in this way, it is possible to reliably display all of the possible meter images, so as a solid effect of reducing the storage capacity of the image and improving the display accuracy of the physical quantity It can be demonstrated.

1 is a schematic configuration diagram illustrating a vehicle display device according to an embodiment of the present invention. It is a schematic diagram for demonstrating the synthesized image displayed by the digital display part of FIG. It is a schematic diagram for demonstrating the maximum meter image memorize | stored in the image memory of FIG. It is a flowchart which shows the production | generation / display flow of the synthesized image displayed by the digital display part of FIG. It is a schematic diagram for demonstrating S103a of FIG. It is a schematic diagram for demonstrating S105 of FIG. It is a schematic diagram for demonstrating S107 of FIG. 4, S108.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic configuration of a vehicle display device 1 according to an embodiment of the present invention. The vehicle display device 1 includes a display 2 and a display control unit 4 and is installed in front of the driver's seat of the vehicle.

(Basic configuration)
First, the basic configuration of the vehicle display device 1 will be described. As shown in FIG. 1, the display 2 is a so-called combination meter including a digital display unit 20 and analog display units 23, 24, 25, and 26.

  The digital display unit 20 has a dot matrix type screen 21 in which a plurality of pixels are arranged on two-dimensional coordinates defined by the X axis and the Y axis, and an image 22 is displayed on the screen 21 facing the driver's seat side. indicate. The digital display unit 20 of the present embodiment is a liquid crystal monitor whose screen 21 is composed of a plurality of liquid crystal pixels, and displays the image 22 in color by driving each of these pixels. Therefore, the image 22 is displayed on the screen 21 based on matrix data expressed by gradation by a plurality of dots individually corresponding to each pixel. Here, the image 22 is displayed so as to indicate a predetermined physical quantity of the vehicle. In this embodiment, the fuel consumption that is the vehicle travel distance per unit fuel quantity is adopted as the physical quantity to be indicated.

  The plurality of analog displays 23, 24, 25, and 26 have pointers 23a, 24a, 25a, and 26a, respectively. The pointers 23a, 24a, 25a, and 26a are individual drive sources 23b, 24b, 25b, and the like, such as stepping motors. It can be rotationally driven by 26b. The hands 23a, 24a, 25a, and 26a indicate a predetermined physical quantity of the vehicle in accordance with each rotational position. Here, as the physical quantity to be instructed by the hands 23a, 24a, 25a, and 26a, for example, the remaining amount of fuel, the coolant temperature, the vehicle speed, the engine speed, and the like are adopted.

  The display control unit 4 includes a control circuit 40, a drawing circuit 41, and an image memory 42. The control circuit 40 mainly composed of a microcomputer is electrically connected to the digital display unit 20 via the drawing circuit 41 and is also electrically connected to the fuel remaining amount meter 6 and the vehicle speed meter 7. As a result, the control circuit 40 acquires the fuel consumption based on the output signals from the fuel fuel gauge 6 and the vehicle speed meter 7 and controls the digital display unit 20 to display the image 22 instructing the acquired fuel consumption. Is output. The control circuit 40 is electrically connected to the drive sources 23b, 24b, 25b, and 26b of the analog display units 23, 24, 25, and 26, and is used as an instruction target by the display units 23, 24, 25, and 26. It is also electrically connected to various sensors (not shown) that output physical quantities. As a result, the control circuit 40 acquires physical quantities to be designated by the analog display units 23, 24, 25, and 26 based on output signals from various sensors, and designates the obtained physical quantities by the hands 23a, 24a, 25a, and 26a. The control command signal is output so as to

  The drawing circuit 41 is composed of, for example, an IC chip such as an ASIC, and is electrically connected to the digital display unit 20, the control circuit 40, and the image memory 42. The image memory 42 is composed of a storage device such as a flash ROM, for example, and previously stores matrix data necessary for displaying the image 22. Based on the matrix data stored in the image memory 42, the drawing circuit 41 controls the driving of each pixel forming the screen 21 of the digital display unit 20 in accordance with a control command signal from the control circuit 40, whereby the image 22 is displayed on the screen 22. 21 is displayed.

(Feature)
Next, the image 22 displayed on the screen 21 of the digital display unit 20 in the vehicle display device 1 will be described in detail. As shown in FIG. 2, the image 22 of this embodiment is a composite image formed by combining the meter image 220, the mask image 221, and the background image 222.

  Specifically, the meter image 220 is directed from the reference coordinate x0 associated with the X coordinate of the specific pixel column in the screen 21 toward the setting direction Xs set to one of the X axis directions (right direction in FIG. 2). Thus, dots of a predetermined color (for example, green) are arranged. Here, for the meter image 220, the number of dots Dx in the setting direction Xs from the reference coordinate x0 is set so as to change in accordance with the fuel consumption that is the physical quantity to be displayed. Further, the dot number Dy in the Y-axis direction of the meter image 220 of the present embodiment is set to a constant number from the reference coordinate x0 toward the setting direction Xs. With these settings, the meter image 220 is displayed in a bar shape (band shape) with a constant width in which the length from the reference coordinate x0 changes according to the physical quantity.

  The mask image 221 is different from the meter image 220 so that the meter image 220 is exposed in the transmission window 221a that is a rectangular range smaller than the outline, and the meter image 220 is masked in a frame shape outside the transmission window 221a. Color (for example, dark blue) dots are arranged on the mask portion. Here, regarding the transmission window 221a, the number of dots in the setting direction Xs from the reference coordinate x0 matches the maximum number of dots Dxmax of the meter image 220 corresponding to the maximum fuel consumption (for example, 20 km / L) that is the maximum value of the display target physical quantity. So that it is set. Further, the number of dots in the Y-axis direction of the transmission window 221a is set so as to coincide with a certain number of dots Dy of the meter image 220 from the reference coordinate x0 toward the setting direction Xs.

  The background image 222 includes dots of a color (for example, gray) different from the meter image 220 and the mask image 221 so as to form the background of the meter image 220 within the transmission window 221a of the mask image 221. Here, for the background image 222, the number of dots from the reference coordinate x0 in the setting direction Xs and the number of dots in the Y-axis direction are set to coincide with those in the transmission window 221a. With this setting, the background image 222 is displayed in a form that fills the non-display range of the meter image 220 in the transmission window 221a of the mask image 221.

  In the present embodiment, the maximum meter image 2200, the mask image 221 and the background image 222 as the meter image 220 are stored in advance in the form of matrix data in the image memory 42 shown in FIG. Here, the maximum meter image 2200 is a meter image in which the transmission window 221a can be completely filled as shown in FIG. 3 by setting the number of dots Dx in the setting direction Xs from the reference coordinate x0 to the maximum number of dots Dxmax. 220. When the maximum meter image 2200 is displayed on the screen 21, the background image 222 is hidden behind the maximum meter image 2200 as shown in FIG.

  According to the present embodiment, the drawing circuit 22 displays the composite image 22 generated by the drawing circuit 41 using the images 2200, 221, and 222 stored in the image memory 42 on the screen 21 of the digital display unit 20. The control circuit 40 outputs a control command signal to 41. Therefore, hereinafter, a generation / display flow of the composite image 22 realized by the control circuit 40 executing the control program will be described with reference to FIG. In the following description, the control circuit 40 outputting a control command signal to the circuit 41 in order to control the drawing circuit 41 will be described as controlling the drawing circuit 41.

  In S <b> 101 in the flow of FIG. 4, the current fuel consumption is acquired as a physical quantity to be displayed by the digital display unit 20 based on output signals from the fuel remaining amount meter 6 and the vehicle speed meter 7. Next, in S102, in order to specify the meter image 220 of the composite image 22 to be currently displayed on the screen 21 of the digital display unit 20, the number of dots Dx in the setting direction Xs from the reference coordinate x0 of the image 220 is determined in S101. A current dot number Dxp corresponding to the acquired current fuel consumption is calculated. Here, for example, in S102 when the current fuel consumption is the maximum fuel consumption, the maximum dot number Dxmax is calculated as the current dot number Dxp.

  Subsequently, in S103, a reduction process is executed. In this reduction process, a reduced meter image 2202 in which the number of dots Dx from the reference coordinates x0 in the setting direction Xs is a reduced dot number Dxr smaller than the maximum number of dots Dxmax is used as a meter image 220 obtained by reducing the maximum meter image 2200. , Generate.

  Specifically, in S103a of the reduction process, the reduction dot number Dxr is set so as to satisfy the reduction condition Cr that is equal to or larger than the current dot number Dxp calculated in S102 and has a minimum dot difference ΔD from the current dot number Dxp. decide. In this embodiment, where N is an integer value smaller than the maximum number of dots Dxmax and n is defined as N integer values from 1 to N, the reduction magnification of the reduced meter image 2202 relative to the maximum meter image 2200 is as follows. , N reduction ratios n / N are assumed. This is based on the fact that the number of stages at which the maximum meter image 2200 can be reduced by the drawing circuit 41 is N according to the performance of the 41. Under this assumption, the value Dxmax · n / N obtained by multiplying each reduction ratio n / N and the maximum number of dots Dxmax is approximated by an integer by a rounding operation that rounds off the decimal part. , N reduced dot numbers Dxr [n] are set as process variables of the control program. Therefore, in S103a of the present embodiment, each of the reduced dot numbers Dxr [n] set in advance is compared with the current dot number Dxp calculated in S102, so that the above-mentioned reduced dot numbers Dxr [n] The number of reduced dots Dxr that satisfies the reduction condition Cr is determined.

  For example, as shown in FIG. 5, assuming that the maximum number of dots Dxmax is 160 dots and the number of reduction stages N is 64, 64 reduction ratios 1/64, 2/64, 3/64 are used as the reduction ratio n / N. ... 64/64 are assumed. Under such assumption, the number of reduced dots Dxr [n] is set in advance to the number of 64 dots 2, 5, 7,. Therefore, when the current dot number Dxp is 5 dots, the 5 dots in FIG. 5B having the reduced dot number Dxr [2] satisfy the reduction condition Cr that is equal to or larger than the Dxp and has the dot difference ΔD having the minimum value 0. , S103a is determined as the reduced dot number Dxr. On the other hand, when the current dot number Dxp is 6 dots, the 7 dots in FIG. 5C, which is the reduced dot number Dxr [3], satisfy the reduction condition Cr that is equal to or greater than the Dxp and has the dot difference ΔD of the minimum value 1. Therefore, it is determined as the reduced dot number Dxr in S103a.

  In S103b of the reduction process of FIG. 4 following such S103a, the drawing circuit 41 is controlled so as to generate a reduced meter image 2202 having the reduced dot number Dxr determined in S103a in the setting direction Xs from the reference coordinate x0. Under this control, the drawing circuit 41 reads the matrix data of the maximum meter image 2200 from the image memory 42 and performs image processing such as dot thinning processing on the data. As a result, matrix data of the reduced meter image 2202 is generated so that the dot number Dx in the setting direction Xs from the reference coordinate x0 becomes the reduced dot number Dxr, and the data is temporarily stored in the internal memory of the drawing circuit 41. It will be. In this embodiment in which the reduced dot number Dxr [N] matches the maximum dot number Dxmax as shown in FIG. 5D, the matrix for the reduced meter image 2202 generated with Dxr [N] as the reduced dot number Dxr. The data matches the matrix data of the maximum meter image 2200.

  Here, since the number of stages N depends on the image reduction performance of the drawing circuit 41 as described above, each reduction dot number Dxr [n] obtained by multiplying a plurality of reduction magnifications n / N by the maximum dot number Dxmax is It becomes a discrete value under the restriction due to the performance. Therefore, in the present embodiment, all of the meter images 220 in which the number of dots Dx from the reference coordinate x0 in the setting direction Xs is 1 to Dxmax cannot be generated by S103b.

  Therefore, in S104 of FIG. 4 after the above reduction processing, the current dot number Dxp calculated in S102 is compared with the reduced dot number Dxr determined in S103a, and the difference between the dot numbers Dxp and Dxr is determined. As a result, when the same determination is made, the process proceeds to S105, whereas when the different determination is made, the process proceeds to S106.

  Here, in S105 which proceeds when the current dot number Dxp and the reduced dot number Dxr are the same, the reduced meter image 2202 generated in S103b is directly combined with the mask image 221 and the background image 222, and the combined image 22 is displayed on the screen 21. The drawing circuit 41 is controlled to display. Under this control, the drawing circuit 41 reads the matrix data of the mask image 221 from the image memory 42 and forms the image 221 on the uppermost layer 421 as shown in FIG. The control circuit 40 reads the matrix data of the background image 222 from the image memory 42 and forms the image 222 on the lowermost layer 422 as shown in FIG. Furthermore, the drawing circuit 41 displays an intermediate layer having a display order lower than the uppermost layer 421 and higher than the lowermost layer 422 for the reduced meter image 2202 expressed by the latest matrix data stored in the internal memory as shown in FIG. In 420, a meter image 220 is formed. The rendering circuit 41 superimposes the reduced meter image 2202 on the background image 222 and superimposes the mask image 221 on the image 2202 by compositing the layers 421, 422, and 420 thus formed. Is generated and displayed on the screen 21 as shown in FIG.

  On the other hand, in S106 of FIG. 4 which proceeds when the current dot number Dxp and the reduced dot number Dxr are different, the dot difference ΔD which is the difference between the dot numbers Dxp and Dxr is acquired. Here, the dot difference ΔD acquired in S106 of the present embodiment is obtained by subtracting the current dot number Dxp from the dot difference ΔD that is confirmed when the reduction condition Cr is determined in S103a, that is, the reduced dot number Dxr. It will match the value ΔD. In the subsequent S107, the drawing circuit is configured to shift the X coordinate of each dot forming the image 2202 in a direction Xop opposite to the setting direction Xs for the reduced meter image 2202 generated as shown in FIG. 7A by S103b. 41 is controlled. At this time, in this embodiment, the acquired dot difference ΔD is instructed to the drawing circuit 41 as the shift width of the X coordinate in S106, so that the circuit 41 applies the latest reduced meter image 2202 stored in the internal memory. Perform dot shift processing of matrix data. As a result, for example, the reduced meter image 2202 ′ whose coordinates are shifted as shown in FIG. 7B has a dot number Dxp that is smaller by ΔD than the reduced dot number Dxr in the setting direction Xs from the reference coordinate x0. In the opposite direction Xop, the image has the number of dots ΔD. For the reduced meter image 2202 ′ whose coordinates have been shifted, the matrix data is temporarily stored in the internal memory of the drawing circuit 41. FIG. 7 shows an example of generating an image 2202 ′ by shifting the reduced image 2202 having the reduced dot number Dxr of 2 dots shown in FIG.

  In S108, which shifts through the execution of S106 and S107, the drawing circuit 41 is controlled so that the reduced meter image 2202 'shifted in S107 is combined with the mask image 221 and the background image 222. Under this control, the drawing circuit 41 generates the composite image 22 in the same manner as in S105 described above, except that the shifted reduced meter image 2202 ′ is formed on the intermediate layer 420 instead of the reduced meter image 2202. . In this case, the shifted reduced meter image 2202 ′ in the composite image 22 displayed on the screen 21 as shown in FIG. 7C is a portion 2202 that is separated from the transmission window 221a by the number of dots ΔD in the opposite direction Xop from the reference coordinate x0. “a” is hidden by the mask image 221 and is not displayed. Therefore, a reduced meter image 2202 ′ after shifting in the composite image 22 is a portion 2202′b of the current dot number Dxp that is smaller than the reduced dot number Dxr by ΔD within the transmission window 221a extending from the reference coordinate x0 in the setting direction Xs. Is displayed.

  Note that after the composite image 22 is displayed on the screen 21 in S108 or S105, the process returns to S101.

  As described above, as the meter image 220 constituting the composite image 22, a reduced meter image 2202 obtained by reducing the maximum meter image 2200 from the reference coordinate x0 or a reduced meter image 2202 ′ obtained by shifting the coordinate in addition to the reduction is generated. Is done. Here, the coordinate-shifted reduced meter image 2202 ′ is obtained depending on the reduced meter image 2202 that has only been reduced out of the meter image 220 in which the number of dots Dx in the setting direction Xs from the reference coordinate x0 is 1 to Dxmax. All images that cannot be displayed can be displayed. Therefore, in this case, since the dot width corresponding to the same fuel consumption value in the setting direction Xs is 1 dot width, the resolution in the fuel consumption display can be maximized. Moreover, the meter image 220 stored in advance in the image memory 42 can be limited to the maximum meter image 2200 having the maximum number of dots Dxmax. For these reasons, the vehicular display device 1 of the present embodiment is a device that can reliably achieve both a reduction in storage capacity in the image memory 42 and an improvement in display accuracy in the digital display unit 20.

  In the embodiments described so far, the image memory 42 corresponds to the “storage means” recited in the claims, and the control circuit 40 that executes S101 and S102 corresponds to the “calculation means” recited in the claims. Correspondingly, the control circuit 40 that executes S103a and S103b of S103 and the drawing circuit 41 jointly constitute the “reduction means” described in the claims, and the control circuit 40 that executes S104 falls within the claims. The control circuit 40 that executes S105 and the drawing circuit 41 jointly constitute the “first synthesizing means” described in the claims, and the control circuit that executes S106 and S107. 40 and the drawing circuit 41 jointly constitute the “shift means” described in the claims, and the control circuit 40 and the drawing circuit 41 executing S108 jointly set forth in the claims. Constitute a "second synthetic means."

(Other embodiments)
Although one embodiment of the present invention has been described above, the present invention is not construed as being limited to the embodiment, and can be applied to various embodiments without departing from the gist of the present invention. Can do.

  Specifically, the physical quantity indicated by the display of the meter image 220 may be various physical quantities related to the vehicle such as the vehicle speed, the engine speed, the remaining amount of fuel, the coolant temperature, etc., in addition to the fuel consumption described above. . In addition, the setting direction to be changed according to the display target physical quantity for the meter image 220 may be any one of the Y-axis directions (for example, the upward direction in FIG. 2). Further, in the direction perpendicular to the setting direction that is varied according to the physical quantity to be displayed for the meter image 220 (in the above-described embodiment, the Y-axis direction), the edge of the meter image 220 in the vertical direction is represented by the mask image 221. The composite image 22 may be generated by masking. Furthermore, the digital display unit 20 that displays the composite image 22 including the meter image 220 on the screen 21 may be, for example, an EL (Electro-Luminescence) monitor other than the liquid crystal monitor described above.

  In addition, in S103a, for integer approximation regarding the value Dxmax · n / N obtained by multiplying each reduction ratio n / N and the maximum number of dots Dxmax, for example, in addition to the truncation operation for truncating the decimal part, You may perform it by various rounding operations, such as a rounding up operation which rounds up, or a rounding off operation which rounds off after a decimal point. In addition, the generation of the reduced meter image 2202 may not be performed in S103b, but may be performed immediately before generation of the composite image 22 in S105 and S107. In addition, if the determination condition Cr of the reduced dot number Dxr in S103 is not less than the current dot number Dxp, the dot difference ΔD from the current dot number Dxp may not be the minimum value. In addition, the present invention is applied to a vehicle display device as a head-up display for displaying a display image on the screen 21 as a virtual image, in addition to the vehicle display device 1 including the display 2 functioning as a combination meter. Is possible.

DESCRIPTION OF SYMBOLS 1 Display apparatus for vehicles, 2 Display, 4 Display control unit, 6 Fuel fuel gauge, 20 Digital display part, 21 Screen, 22 Image / composite image, 23, 24, 25, 26 Analog display part, 40 Control circuit, 41 drawing circuit, 42 image memory (storage means), 220 meter image, 221 mask image, 221a transmission window, 222 background image, 420 intermediate layer, 421 top layer, 422 bottom layer, 2200 maximum meter image, 2202 reduced meter image 2202 ′ shifted / shifted reduced meter image, Cr reduction condition, Dx dot number, Dxmax maximum dot number, Dxp current dot number, Dxr, Dxr [n] reduced dot number, n / N reduction magnification, x0 standard Coordinate, Xs setting direction, Xop opposite direction, ΔD dot difference

Claims (3)

A meter image that is represented by dots arranged in the setting direction from the reference coordinates and in which the number of dots in the setting direction from the reference coordinates changes according to the physical quantity to be displayed, and the number of dots in the setting direction from the reference coordinates A display device for a vehicle that displays a composite image of a mask image that masks the meter image outside the range that is the maximum number of dots according to the maximum physical quantity, on a dot matrix type display,
Storage means for storing in advance a maximum meter image as the meter image in which the number of dots in the setting direction from the reference coordinates is the maximum number of dots, and the mask image;
Calculating means for calculating the current number of dots according to the current physical quantity as the number of dots in the setting direction from the reference coordinates of the meter image to be displayed on the display;
By reducing the maximum meter image stored in the storage means, a reduced meter image is generated as the meter image in which the number of dots in the setting direction from the reference coordinates is smaller than the maximum number of dots. Reducing means to
Determining means for determining the difference between the current dot number calculated by the calculating means and the reduced dot number of the reduced meter image generated by the reducing means;
When the determination is made by the determination unit, the reduced meter image generated by the reduction unit is directly combined with the mask image stored in the storage unit to generate the composite image. Combining means;
The dot difference between the current dot number calculated by the calculating unit and the reduced dot number of the reduced meter image generated by the reducing unit when the determination unit makes a different determination, the reduction Shift means for shifting the dot coordinates of the meter image in a direction opposite to the setting direction;
Second combining means for generating the composite image by combining the reduced meter image shifted by the shift means with the mask image stored in the storage means;
A vehicle display device comprising: When N is defined as an integer value smaller than the maximum number of dots, and n is defined as a plurality of integer values from 1 to N, the number of reduction dots is the number of reduction magnifications n / N and the maximum number of dots. Multiple values are set by integer approximation for the value obtained by multiplying
The reduction means generates the reduction meter image so that the reduction dot number equal to or greater than the current dot number calculated by the calculation means among the plurality of reduction dot numbers set. The vehicle display device according to claim 1.   The reduction means has a reduction dot number that is equal to or larger than the current dot number calculated by the calculation means and minimizes a dot difference from the current dot number among the plurality of reduction dot numbers set. The vehicle display device according to claim 2, wherein the reduced meter image is generated.