JP6004701B2 - Display device and vehicle air conditioner equipped with the same - Google Patents

Description

  The present invention provides a display device that displays characters and figures by emitting light on an operation panel such as an electronic device, a vehicle air conditioner, or an audio, a switch knob including such a display device, and the switch knob. The present invention relates to a vehicle air conditioner.

  In order to ensure visibility in dark places such as at night, there is a method in which characters and figures on the operation and display surfaces of various switches are illuminated with illumination behind the display surface as in Patent Document 1 to make the characters appear. Are known. This display surface consists of a resin-made translucent member and a light-shielding member. When a light source appropriately placed on the back side of the display surface is lit in the dark, only the translucent member is brightened and characters and figures are displayed on the display surface side. The

As a method for realizing such a display, two-color molding, which is a kind of resin injection molding, is excellent in terms of manufacturing cost and durability, and is widely used. Unevenness (dark areas) may occur on the surface, which may impair visibility and appearance.
For example, when displaying a character or a figure surrounding a background region made up of a light shielding member by a line constituting the character or figure by a translucent member such as “O” or “P”, the enclosed light shielding member is injection molded. Therefore, it is necessary to provide a bridge made of a light-shielding member, and when this bridges a line made of a translucent member, a shadow is cast on the display surface, resulting in a part of the character becoming dark. Patent Document 2 discloses a technique for removing a bridge when a light shielding member is released.

JP 2003-346585 A JP 2009-298005 A

  These characters and figures are preferably displayed clearly without uneven brightness. If a plurality of switches having poor visibility are arranged, there is a risk that an inappropriate switch is erroneously operated. It is a burden for the operator to operate the switch while being wary of an erroneous operation.

A configuration example of the display device is shown in FIG.
The display device 31 has a display surface 32, and the translucent member 34 exposed on the display surface 32, which is generally composed of the light shielding member 35, forms characters or figures 38. When the light source is turned on, light emitted from a light source 33 (not shown) located on the back side of the display surface 32 is transmitted through the translucent member 34, and a character or graphic 38 is lit on the display surface 32.

The unevenness of the brightness of the characters or the graphic 38 on the display surface 32 when the light source 33 is turned on means that there is a portion with low luminance. In a portion where the brightness is low, the thickness w1 ′ of the line constituting the character or figure 38 is not sufficient, and the light is reduced when passing through the light transmitting member 34, or the bridge 37 made of the light blocking member is lighted. This occurs, for example, when a shadow 39 is present at a location on the road where the display surface 32 should emit light.
If the thickness w1 ′ of the line constituting the character or figure 38 is not sufficient, it can be avoided by making the character or figure 38 sufficiently thick, but the design of the character or figure 38 is restricted because a thin line cannot be adopted. . Further, when a shadow 39 is generated on a character or figure 38 by a bridge 37 made of a light shielding member, it can be avoided by removing the bridge 37 as in the above-mentioned Patent Document 2, but complicated procedures and specials are necessary for the removal. A simple molding method is required.

  This invention is made in view of such a situation, Comprising: The display apparatus which improved the visibility by reducing the nonuniformity of the brightness | luminance of the whole character and a figure, and a vehicle air conditioner provided with the same are provided. With the goal.

In order to solve the above-described problems, the display device of the present invention and the vehicle air conditioner including the same employ the following means.
That is, the display device of the present invention includes a light transmissive member that transmits light of a light source disposed on the back side of the display surface to the display surface, and a light shielding member that blocks the light, and the light transmissive member includes: The light-transmitting member is disposed in a state of penetrating the light-shielding member from the display surface toward the back side, and the light-transmitting member exposed to the display surface emits light by transmitting light transmitted through the light-transmitting member to display characters or figures. In the display device, the translucent member includes a first part that forms a part of the character or graphic and a part of the character or graphic that is thicker on the display surface side than the first part. The light transmitting member has a thickness on the light source side rather than a thickness on the display surface side in a range in which the light transmitting member penetrates the light shielding member in the direction of the light source from the display surface. Is thicker, the light source side and the display surface side of the translucent member Inclination angle of the side surface of the light transmitting member due to the difference in thickness, viewed contains a portion to be at least twice the draft angle required for demolding by molding a light-transmissive member by injection molding, said first The ratio of the thickness on the light source side to the thickness on a part of the display surface is larger than the ratio of the thickness on the light source side to the thickness on the display surface of the second part .
Here, the translucent member only needs to transmit light emitted from the light source, and the transparency is not limited, but the present invention is particularly effective when the translucency of the translucent member is low.

  Usually, when an attempt is made to produce a translucent member that guides light from the light source on the back surface to the display surface by injection molding or the like, a draft of about 1 to 2 degrees is given to the side surface for mold release. The draft is about 5 degrees when the surface is textured. These are only for the purpose of mold release, not for the purpose of light collection. In the display device of the present invention, since the thickness on the light source side of the translucent member is increased by providing a gradient more than twice the normal draft, conventionally, the light is not incident on the translucent member due to the light shielding member. The light from the light source also enters the translucent member. As a result, the amount of light reaching the display surface increases, and the portion that makes the operator feel the darkness of the displayed characters and figures decreases.

  Here, human vision has a dynamic range, and if there is a part having a certain level of luminance in the visual field, it is difficult to distinguish the luminance of that part. On the other hand, even if light is emitted, the relatively low brightness area has a brightness that is not significantly different from that of the area that does not emit light. Therefore, it is easy to visually distinguish between dark and light, and the operator has uneven brightness in characters or figures. Recognize. When the present invention is applied to the entire translucent member of a character or figure display device in which unevenness in brightness is recognized due to this visual characteristic, unevenness in brightness of the displayed character or figure as a whole is visually reduced.

At this time, even if the luminance of the portion is increased by applying the present invention to a portion having sufficient luminance even if the present invention is not applied, the operator hardly notices that the luminance has increased. On the other hand, when the present invention is applied to a portion where unevenness in luminance is recognized, the low luminance increases and it becomes clear that it is brighter than the surroundings. For this reason, if the present invention is applied to the entire displayed character or figure, the difference between the upper limit and the lower limit of the brightness recognized by the operator is reduced, so that the operator is less likely to feel uneven brightness and the displayed character is displayed. Or the distinctiveness of a figure improves and the appearance of a character and a figure improves.
As a result, it becomes possible to adopt a design of characters and figures using thin lines that could not be adopted because of a decrease in luminance.

  Furthermore, in the display device of the present invention, in the above-described display device, a ratio between a thickness of the light transmitting member on the display surface and a thickness of the light transmitting member on the light source side corresponding thereto is It is characterized in that it is set so that the luminance of each part of a line constituting a character or graphic displayed on the display surface by transmitted light does not fall below a predetermined threshold.

In the above-described display device, although the difference in visual luminance between displayed characters or graphics is reduced, the overall luminance is uniformly improved.
The impression that the brightness level gives to the operator may vary depending on the shape of the displayed character or figure, the location where it is used, the brightness of the surroundings, etc. The operator may recognize that it has become brighter.
Therefore, in the display device of the present invention, it is assumed that a threshold value is set on the assumption of an environment to be used in advance, and a portion below this is a portion having low luminance. If only the translucent member of the corresponding part on the light source side is made thick without changing the width (thickness) of the translucent member on the display surface side of the part where the brightness of the characters or figures is low, the brightness is low on the display surface side Only the brightness of the part can be increased. At this time, the portion where the luminance of the character or the figure is high does not become excessively bright if the light-transmitting member of the corresponding portion on the light source side is also made thicker than the draft.
By making only the shape of the translucent member where the brightness is relatively low selectively the shape that allows light to easily pass through, the part that is originally bright enough does not become brighter than necessary, and the displayed characters and figures Since the luminance is in a certain range, the luminance unevenness is reduced as a result, the discrimination is improved, and the appearance is improved.

  Furthermore, in the display device of the present invention, in the above-described display device, the surface on the light source side of the light transmissive member is convex in the portion where the thickness of the light transmissive member is increased, thereby improving the light collecting property. It is characterized by that.

  In the present invention, since the surface of the light transmitting member on the light source side has a convex shape (i.e., a semi-cylindrical shape along the direction of characters or figures on the display surface), incident light from the light source can easily reach the display surface. The brightness of the corresponding part of the character or figure can be further increased. This convex shape is desirably determined by optical design such as optical path simulation (ray tracing). Moreover, if the translucent member is formed by injection molding, an extra manufacturing cost associated with the convex shape is not generated.

Further, the display device of the present invention is a display device according to any of the above, the translucent member and the light shielding member is characterized in that a two-color molding.

Since the display device of the present invention is manufactured by two-color molding of the light-transmitting member and the light-shielding member, it can be manufactured at a lower cost than a method in which the display surface is painted once and the character portion is laser-cut. it can. In addition, since the light shielding member itself is colored, it is more advantageous than painting in terms of durability against wear and abrasion.
The conventional translucent member in two-color molding has a difference in thickness only between the display surface side and the light source side, so that if the line to be displayed is thin, a portion with low luminance may occur. However, since the thickness on the light source side of the translucent member is made thicker than that on the display surface side, it is possible to avoid occurrence of a portion with low luminance.

  Furthermore, the display device of the present invention is the above-described display device, and is located on the light source side that blocks light incident on the light-transmissive member from the light source when the two-color molding is performed, and the light shielding A bridge formed of a member is provided, and the thickness of the translucent member on the light source side is thicker in the vicinity of the bridge than in a portion other than the vicinity of the bridge.

  In two-color molding, in order to display a figure with an inner region surrounded by a line, a bridge of the light shielding member straddling the translucent member that is a line surrounding the light shielding member forming the inner region is formed on the surface on the light source side. Although necessary, since this bridge blocks light incident from the light source, the corresponding portion of the display surface becomes dark. If the change in the thickness of the translucent member is about the draft, a shadow may occur in the corresponding part of the character or figure.

  Furthermore, in the display device of the present invention, the vicinity of the location where the bridge straddles, that is, the range that is affected as shadow or darkness on the display surface, is selected, and the thickness of the light-transmitting member on the light source side of the location is more than other. By increasing the thickness, the influence of the bridge can be offset by the light entering the translucent member from the light source and traveling around the back side of the bridge, and the reduction in luminance can be reduced. Although it depends on the transparency of the translucent member, not only the thickness of the translucent member is increased but also the translucent member is increased in the light source direction, that is, the volume of the translucent member between the bridge and the display surface is increased. The decrease in luminance due to the influence of the bridge can also be reduced by increasing the amount of light that goes around the back of the bridge.

In order to avoid the influence of the bridge, a method of removing the bridge itself may be adopted (Patent Document 2, etc.), but there is a problem that the molding procedure and the mold become complicated and costly. According to the display device of the present invention, the influence of the bridge on the display can be reduced without removing the bridge.
In addition, there is a method of blurring the shadow of the light shielding member bridge appearing on the display surface by lowering the transparency of the translucent member. However, since the thin line becomes darker by lowering the transparency, the design of characters or figures is restricted.

Furthermore, the display device of the present invention is the above-described display device, wherein the light transmitting member is a primary injection product , the light shielding member is a secondary injection product, and a part of a side surface of the light transmission member. Alternatively, the entire gradient is 10 degrees or more and 45 degrees or less.

In injection molding, the normal draft for the purpose of mold release is about 1 degree to 2 degrees, and it is about 4 degrees to 5 degrees even when the surface is textured, but the display device of the present invention improves the brightness. By defining the gradient of the location to be 10 degrees or more and 45 degrees or less, which greatly exceeds these, luminance unevenness is reduced.
If the slope of 10 degrees or more and 45 degrees or less is provided not only on the side surface of the entire translucent member of characters and figures displayed as described above but only on a portion that is dark unless the present invention is applied, Bright areas will not be brighter than necessary, only the brightness of dark areas will increase, and the brightness of the resulting characters and figures will be in a certain range, reducing unevenness in brightness and improving discrimination, It looks better and is even more effective.
In addition, as shown in FIG. 4, the side surface of the translucent member may not have a constant inclination. The gradient in this case can be obtained approximately from the thickness of the light transmitting member on the light source side and the thickness on the display surface side, and the thickness of the light shielding member around the corresponding portion (in the direction of penetration of the light transmitting member). it can.

  Furthermore, the display device of the present invention is any one of the above-described display devices, and is characterized by integrally including the light source.

Since the display device of the present invention includes the light source integrally, it is not necessary to separately attach the light source and the display device when the display device is assembled, and the display device can be easily assembled.
Further, since the positional relationship between the displayed character and the light source is fixed, it is possible to avoid the occurrence of uneven brightness on the display surface due to the displacement of the light source position during assembly.

  Furthermore, the display device of the present invention is any one of the display devices described above, and is characterized by being an operation knob of a switch.

  In the display device of the present invention, when the switch operating knob emits light, the position of the switch can be easily grasped at night or in a dark place, so that it is possible to operate the switch without preparing separate lighting. If it is difficult to identify by light emission, it takes time to specify the switch to be operated. In the above display device, the unevenness of the brightness of the operation knob of the switch that emits light is reduced and the visibility is improved. Therefore, even when a plurality of switches are arranged, the target switch can be easily specified and operated. become able to.

  Moreover, the vehicle air conditioner of this invention is equipped with the above-mentioned display apparatus as an operation knob of a switch, It is characterized by the above-mentioned.

Vehicle air conditioners are often operated during driving and are often operated at night. Also, if the environment is bright during the day, the driver who is an operator is accustomed to the brightness outside the vehicle, and it is difficult to quickly grasp the switches in the relatively dark vehicle.
Since an operation knob of a switch to which the display device of the present invention is applied has good visibility, the position of the target switch can be specified at a glance. In addition, even if the inside of the vehicle is relatively darker than the outside due to clear weather during the day, if the characters on the operation knob of the switch are lit according to the present invention, the brightness of the characters can be increased evenly. The position of the switch can be easily identified, and the time for the driver to look away from the operation knob of the vehicle air conditioner is reduced, which contributes to driving safety.

According to the display device of the present invention, the thickness of the light transmissive member that penetrates the light shielding member is made thicker on the light source side than on the display surface side. The light from the light source that did not enter will also enter the translucent member, increasing the amount of light that reaches the display surface, and reducing the darkness of characters and figures displayed to the operator. .
This makes it difficult for the operator to perceive variations in brightness, improves display discrimination, and allows the design of characters and figures that use thin lines that could not be used because of a decrease in brightness. become.

1 is a perspective sectional view of a display device according to a first embodiment of the present invention. It is a front view of the display apparatus of 1st Embodiment of this invention. It is a figure which shows the display apparatus of 2nd Embodiment of this invention. It is a figure which shows the cross-sectional example of the translucent member which concerns on 2nd Example of this invention. It is a figure which shows the manufacture procedure of the display apparatus which concerns on 4th Example of this invention. It is a figure which shows the primary injection and secondary injection which concern on 4th Example of this invention. It is a perspective sectional view showing a conventional display device.

Embodiments according to the present invention will be described below with reference to the drawings.
[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 and 2.

FIG. 1 shows a display device 1 according to this embodiment applied to an operation knob of a switch of a vehicle air conditioner.
The display device 1 includes a light transmissive member 4 and a light shielding member 5. A resin made of a material that transmits light from the light source 3 is used for the translucent member 4. For the light shielding member 5, a resin made of a material that shields light from the light source 3 is used.
The display device 1 has a display surface 2. On the display surface 2, a character 8 "AUTO" is arranged as shown in FIG. FIG. 1 shows a cross section of the character 8 at the position AA of “O”. A light source 3 (not shown) such as an LED is disposed on the back side of the display surface 2. The display surface 2 is generally composed of a light shielding member 5, and the characters 8 are formed by exposing the light transmitting member 4 penetrating the light shielding member 5 to the display surface 2.

  In the range L where the translucent member 4 penetrates the light shielding member 5 from the display surface 2 toward the light source 3, the translucent member 4 is thicker on the light source 3 side than the thickness w1 on the display surface 2 side. It has become.

  The inner side 6 of the letter “O” becomes an isolated light shielding member 5 surrounded by the translucent member 8. In order to form the light shielding member 5 by one injection, a bridge 7 is used that connects the light shielding member 6 isolated on the display surface 2 side on the back side.

When manufacturing a translucent member by injection molding, a draft is required for mold release. In the above-described FIG. 7, the relationship of w2 ′> w1 ′ is established in the range L ′ where the translucent member 34 penetrates the light shielding member 35. Here, when the draft is a constant angle θ, the relationship is tan θ = (w2′−w1 ′) / 2 / L ′.
In normal injection molding, the draft angle θ for mold release is set to 1 degree to 2 degrees. In the case where the surface of the member is subjected to the embossing process, it is difficult to release the mold at 1 degree to 2 degrees, so that the draft is increased. However, in the case of the embossing process, generally 4 degrees to 5 degrees is a standard.

  In the display device 31 of FIG. 7, since it has a normal draft, w2 ′ has substantially the same width as w1 ′, and most of the incident light from the light source is blocked by the light blocking member 35 and reaches the surface 32 side. The rate is low. When the line width (thickness) w1 ′ of a character or a figure becomes 0.8 mm or less by the trial production of the display device 31, the inventors of the present invention recognize light unevenness remarkably with a normal draft for a release purpose. I have found that. On the other hand, in this embodiment, since the gradient is larger than the normal draft, the width w2 of the translucent member 4 is increased, and the translucent member 4 enters the range L that penetrates the light shielding member 5. The incident light increases more than before, and the incident light is collected by reflection or refraction at the boundary with the light shielding member 5 in the translucent member 4. As a result, the amount of light reaching the display surface 2 increases, and the character 8 displayed on the display surface 2 becomes brighter even if the light source 3 is equivalent to the conventional light source 33 (see FIG. 7).

  The inventors of the present invention prototyped a display device with a large draft angle, and even if the line width (thickness) w1 is such that a character or figure line becomes dark with the conventional draft angle, If the width (thickness) w2 is made sufficiently large so that the angle is more than twice that of the standard draft, the portion that makes the operator feel the darkness of the characters on the display surface is reduced, that is, uneven brightness is noticeable. I found out what I can do. In the trial production, if the draft is about 30 degrees, even if the line width w1 of the character or figure is about 0.8 mm, it is displayed stably and looks good regardless of the shape or part. If the gradient is set to 10 degrees or more, generally necessary luminance is ensured. If the draft angle is too large, the light shielding member 4 becomes thin and cannot completely shield the light or the edges of the characters or the figure 8 become unclear or interfere with the draft angle of other parts. Up to about 45 degrees is appropriate.

As described above, according to the present embodiment, the following operational effects are obtained.
Since the translucent member 4 is formed by injection molding and is made at least twice the draft necessary for die cutting and the translucent member 4 is thickened on the light source 3 side, more light is translucent. Can be made incident. As a result, the amount of light reaching the display surface is increased, and the portion that makes the operator feel the darkness of displayed characters and figures can be reduced.

In particular, in the present embodiment, since a draft larger than usual is adopted for the entire translucent member 4 of the display device 1 of the character or figure 8 whose brightness is recognized by the operator, the displayed character or figure 8 is displayed. The overall brightness can be increased.
Due to the characteristics of human vision, even if the luminance of a portion with sufficient luminance increases, the operator is difficult to notice that the luminance has increased. On the other hand, when the present invention is applied to a portion that is recognized as dark, the low brightness increases, and it becomes clear that it is brighter than the periphery that does not emit light. For this reason, if the present invention is applied to the entire displayed character or figure as in the present embodiment, the difference between the upper limit and the lower limit of the brightness recognized by the operator is reduced, so that the operator hardly perceives uneven brightness. Thus, the identification of the displayed character or figure is improved and the appearance of the character or figure is improved.
This makes it possible to adopt a design of characters and figures 8 using thin lines that could not be adopted because the luminance is lowered.

In addition, since the display device 1 is applied to an operation knob of a switch of a vehicle air conditioner, if the switch operation knob emits light, the position of the switch can be easily grasped at night or in a dark place. The switch can be operated, and even if a plurality of switches are arranged, the target switch can be easily specified and operated.
Since the operation knob of the switch to which the display device 1 of this embodiment is applied has good visibility, the position of the target switch can be specified at a glance. In addition, even in an environment where the inside of the vehicle is relatively darker than the outside due to clear weather during the day, visibility can be improved and the switch position can be easily identified by driving the letters on the switch operation knob. It also contributes to safety.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG. 3A shows only the translucent member 14, and FIG. 3B shows the display device 11 formed by injection-molding the light shielding member 15 thereon.
The present embodiment is different from the first embodiment in that the brightness of the displayed character or figure 8 as a whole is not increased, but the brightness is improved only in a portion that is felt dark.

FIG. 3A shows that the thickness of the translucent member 14 is partially changed. That is, since the bridge 17 is present, the thickness of the translucent member 14 is increased in the peripheral portion 19 where the brightness reduction due to the shadow of the bridge 17 is required, and the brightness reduction due to the shadow of the bridge 17 is unnecessary. As for, the translucent member has a wall shape with an inclination of a normal draft.
Further, in the vicinity of the bridge 17 of the translucent member 14, aiming to improve the light collecting efficiency by the convex lens, the translucent member 14 is convex toward the light source 13 side (kamaboko along the direction of characters or figures on the display surface) Shape). Here, in the case where the light can be sufficiently collected only by increasing the thickness in the direction parallel to the display surface, the translucent member 4 is formed as in the vicinity of the bridge 7 in FIG. The surface on the light source 3 side may be flattened. On the other hand, with respect to the portion where the brightness can be ensured even if the exposed character or the line of the symbol 18 is thinned, by making the translucent member 14 not thick, a part of the character or figure is more than necessary. It can be avoided that the lines of the figure become too bright, resulting in uneven brightness.

  In the present embodiment, the surface of the light transmissive member 14 on the light source 13 side is thickened in a convex shape (the shape of the surface along the direction of characters or figures on the display surface), so that incident light from the light source reaches the display surface. Since it becomes easy to do, the brightness | luminance of the applicable part of a character or a figure can be raised locally. However, this convex shape is determined by optical design such as optical path simulation (ray tracing) including the material selection of the translucent member, since the display may become darker if the transparency of the translucent member is lowered. It is desirable. Moreover, if the translucent member is formed by injection molding, there is no extra manufacturing cost associated with the use of the convex shape other than the mold.

Here, the gradient of the side surface of the translucent member 14 does not have to be uniform, and various cross-sectional shapes can be employed as shown in FIG. 4 as an example.
FIG. 4A schematically shows the above-described penetrating portion. Since the taper has a constant slope, there is an advantage that an injection mold can be easily manufactured.
Even if the penetrating portion is formed in a stepped shape as shown in FIG. 4B, it is expected that the luminance is improved as compared with the conventional display device having only the draft angle.
If the penetrating portion is formed in a convex curved surface as shown in FIG. 4C, an improvement in light collection efficiency is expected.
If the display surface side of the penetrating portion is made thin as shown in FIG. 4D, the thickness of the edge of the light shielding member can be secured, so that the light shielding property is improved, while the amount of light incident on the penetrating portion can also be expected. It is expected that and figures can be displayed clearly.
These various cross-sectional shapes can be appropriately selected and combined depending on the properties of the light-transmitting member and the light-shielding member, the usage environment, and the like.

As described above, according to the present embodiment, the following operational effects are obtained.
In the display device 11 of the present embodiment, a threshold value is set on the assumption that the environment is used in advance, and the portion of the character or graphic 18 that falls below this is assumed to be a portion with low luminance. Then, only the thickness of the translucent member 14 of the corresponding portion on the light source 13 side is increased without changing the width (thickness) of the translucent member on the display surface side of the portion where the luminance of the character or graphic 18 is low. Thereby, only the brightness | luminance of the part where the brightness | luminance was low on the display surface 12 side can be made high.
Further, by making only the shape of the light-transmitting member 14 where the luminance is relatively low selectively the shape 19 through which light is easily transmitted, a sufficiently bright portion is not brightened more than necessary and is displayed. Since the brightness of the characters and graphics 18 are in a certain range, uneven brightness is reduced as a result, the discrimination of the characters or graphics 18 displayed on the display surface 12 of the display device 11 is improved, and the appearance is improved. .

[Third Embodiment]
FIG. 5 shows a procedure for manufacturing the display device 1 of the first embodiment described above by two-color molding. Note that the display device 11 of the second embodiment can also be manufactured by a similar method.
First, the translucent member 4 is injection-molded through a resin injection path (not shown) by the translucent member display surface side molding die 21 and the translucent member light source side molding die 22 (FIGS. 5A and 6 (a). a)).
The light transmitting member 4 is obtained by releasing from the light transmitting member display surface side mold 21 and the light transmitting member light source side mold 22 (see FIG. 5B).
Subsequently, the translucent member 4 is placed on the light shielding member display surface side mold 23 and the light shielding member light source side mold 24 (see FIG. 5C).
A light shielding resin is injection-molded to form the light shielding member 5 (see FIG. 5D).
The display device 1 is obtained by separating from the light shielding member display surface side molding die 23 and the light shielding member light source side molding die 24 (see FIGS. 5E and 6B).

In each of the above-described embodiments, the light source has been described on the assumption that it is separate from the display device. However, the display device of the present invention may be provided integrally with the light source.
By integrating the display device and the light source, it is not necessary to separately attach the light source and the display device when the display device is assembled, and the display device can be easily assembled.
Further, if the positional relationship between the displayed character and the light source is fixed, the position of the light source is shifted at the time of assembly, and it is possible to avoid the occurrence of uneven brightness on the display surface as individual differences.

  Although the display device of each embodiment described above has been described as an operation knob of a switch of a vehicle air conditioner, the present invention is not limited to this, and is used for, for example, a switch panel of another electronic device or the like. can do.

1, 11, 31 Display device 2, 12, 32 Display surface 3, 13, 33 Light source 4, 14, 34 Translucent member 5, 15, 35 Light blocking member 6, 16, 36 Isolated light blocking member 7, 17, 37 Bridge 8, 18, 38 Characters or graphics 19 Location where draft angle is locally increased 21 Display surface side molding die 22 for light transmitting member Light source side molding die 23 for light transmitting member Display surface side molding die 24 for light shielding member For light shielding member Light source side mold
39 Shadow of the bridge

Claims (9)

A translucent member that transmits light from a light source disposed on the back side of the display surface to the display surface;
A light shielding member that shields the light,
The translucent member is arranged in a state of penetrating the light shielding member from the display surface toward the back side,
A display device that displays characters or figures by emitting light from the transparent member exposed to the display surface with transmitted light that passes through the transparent member,
The translucent member has a first part that forms a part of the character or graphic and a second part that forms a part of the character or graphic and is thicker on the display surface side than the first part. In the range where the translucent member penetrates the light shielding member in the direction of the light source from the display surface, the translucent member is thicker on the light source side than on the display surface side. And
The inclination angle of the side surface of the translucent member due to the difference in thickness between the light source side and the display surface side of the translucent member is necessary when the translucent member is molded by injection molding and die-cut. only contains a portion to be more than twice of a draft,
The ratio of the thickness on the light source side to the thickness on the display surface of the first portion is larger than the ratio of the thickness on the light source side to the thickness on the display surface of the second portion. Display device.   The ratio of the thickness of the translucent member on the display surface and the corresponding thickness of the translucent member on the light source side constitutes a character or figure displayed on the display surface by the transmitted light The display device according to claim 1, wherein the display device is set so that the luminance of each portion of the line to be performed does not fall below a predetermined threshold value.   The display device according to claim 2, wherein the light-transmitting member has a light-projecting surface at a portion where the thickness of the light-transmitting member is increased to improve the light collecting property. The translucent member and the light blocking member, a display device according to any one of claims 1 to 3, characterized in that the two-color molding. While positioned on the light source side from the front Symbol source block light incident on the light transmitting member comprises a bridge formed by the light shielding member,
5. The display device according to claim 4, wherein the thickness of the translucent member on the light source side is thicker in the vicinity of the bridge than in portions other than the vicinity of the bridge. The translucent member is a primary injection product ,
The light shielding member is a secondary injection product ,
The display device according to claim 4 or 5, wherein a gradient of a part or all of the side surface of the translucent member is 10 degrees or more and 45 degrees or less.   The display device according to claim 1, wherein the light source is integrally provided.   The display device according to claim 1, wherein the display device is an operation knob of a switch.   A vehicle air conditioner comprising the display device according to claim 8 as an operation knob of a switch.

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