JP5915247B2 - Display device - Google Patents

Description

  The present invention relates to a display device mounted on a vehicle, for example.

  As this type of display device, for example, those described in Patent Documents 1 and 2 below are known. The display device described in Patent Literature 1 below includes a liquid crystal cell having a display portion that is switched between a transmissive state and a non-transmissive state by selective voltage application between a pair of transparent electrodes, and a light source that illuminates the liquid crystal cell. And a diffusion plate that is disposed between the light source and the liquid crystal cell and diffuses light from the light source, and the surface of the diffusion plate is colored so that the light from the light source is colored orange or the like when the light source is turned on A layer is provided, and the background portion of the display portion of the cell is colored in orange or the like by this colored layer.

  On the other hand, the display device described in Patent Literature 2 below illuminates the liquid crystal cell having a liquid crystal cell having a display portion that is switched between a transmissive state and a non-transmissive state by selective voltage application between a pair of transparent electrodes. A light source and a transmissive type that is disposed between the light source and the liquid crystal cell, transmits incident light from the front side through the liquid crystal cell and reflects the incident light from the front side to the liquid crystal cell side, and transmits backlight from the light source to the liquid crystal cell side. The display part and the background part of the liquid crystal cell are reflected by the light reflected by the transmissive reflector when the light source is turned off and by the light (transmitted light) transmitted through the transmissive reflector when the light source is turned on. The contrast with is clear. In addition, the background part visually recognized by the reflected light of a transmissive | pervious reflector is the color (for example, gray) of transmissive reflector itself.

JP 2007-052364 A Japanese Patent Application Laid-Open No. 11-311777

  However, the display device disclosed in Patent Document 1 discloses a display panel in which the brightness is changed by gradually changing the size of dots. Such dots on the display board have a non-contact area where adjacent dots do not contact and a contact area where adjacent dots contact, and the brightness changes abruptly at the boundary between the non-contact area and the contact area. There has been a concern that a tone jump phenomenon that appears to be occurring occurs and the observer sees the boundary.

  The present invention has been made in view of this point, and provides a display panel that does not stand out even if a tone jump phenomenon occurs.

In order to achieve the above object, the present invention provides
A liquid crystal cell having a display portion that is switched between a transmissive state and a non-transmissive state by selectively applying a voltage between a pair of transparent electrodes, a light source that illuminates the liquid crystal cell, and between the light source and the liquid crystal cell A display device comprising: a transmissive reflector that is disposed and reflects incident light that is transmitted through the liquid crystal cell and is incident from the front side toward the liquid crystal cell side, and transmits backlight from the light source toward the liquid crystal cell side In
The transmissive reflector has a translucent first colored portion that colors a background portion of the display portion, and second colored portions that are continuously arranged with a predetermined interval,
The first colored portion is composed of a dot colored portion in which the dot size gradually changes,
The second colored portion can make it difficult to visually recognize the boundary even if a tone jump phenomenon occurs by covering the dot colored portion.

  In the present invention, the second coloring portion covers the tone jump generated by the dot coloring portion, so that it is difficult to visually recognize even when a tone jump occurs.

According to the present invention, it is possible to provide a display device that can achieve the initial purpose and hardly recognize the boundary even if a tone jump phenomenon occurs.

1 is a cross-sectional view of a display device according to a first embodiment of the present invention. Sectional drawing of the transflective board in the 1st Embodiment of this invention. The front view of the transflective board in the 1st Embodiment of this invention. Detailed drawing of the 1st coloring part in a 1st embodiment of the present invention. Detailed drawing of the transflective board in the 2nd Embodiment of this invention. Detailed drawing of the transflective board in the 3rd Embodiment of this invention. The detail drawing of the transflective board in the 4th Embodiment of this invention. The detail drawing of the transflective board in the 4th Embodiment of this invention.

1 to 4 show a first embodiment of the present invention.

1 and 2, the display device according to the present embodiment is mounted on a vehicle such as an automobile or motorcycle, for example, and includes a circuit board 1, a cell case 2, a light source 3, a liquid crystal cell 4, and a transmission type. The reflector 5 is provided.

The circuit board 1 is, for example, a well-known hard circuit board, and the light source 3 and the liquid crystal cell 4 are electrically connected.

The cell case 2 is made of, for example, milky white synthetic resin material, and is disposed on the circuit board 1 to house the light source 3 and to support the liquid crystal cell 4 from behind.

  The light source 3 is made of a light emitting diode, for example, and illuminates the liquid crystal cell 4 from behind.

  The liquid crystal cell 4 is, for example, a TN or STN type, and is switched between a transmissive state and a non-transmissive state by selectively applying a voltage between a pair of transparent electrodes formed in a pair of glass substrates enclosing liquid crystal molecules. A display unit 41 is provided.

  Further, as shown in FIG. 3, the display unit 41 displays the tachometer TA, the speedometer SP, and the fuel meter FU in the non-transparent region, and the background in the transparent region around the display unit 41. Part 42 is formed.

  In the present embodiment, the display unit 41 includes a fixed display unit 41a that is always in an opaque state when a voltage is applied, and a variable display unit 41b that switches between a transparent state and an opaque state in accordance with a change in a measurement target. However, the fixed display portion 41a may be replaced with printing or the like.

  The tachometer TA includes a fixed display unit 41a composed of a number part, and a variable display unit 41b composed of a bar graph whose length changes in conjunction with a change in the engine speed and indicating a predetermined fixed display unit 41a. Yes.

  The speedometer SP includes a fixed display portion 41a composed of “km / h” and a variable display portion 41b composed of “day” character segments for displaying numerical values corresponding to the speed.

  The fuel meter FU has a print display portion D composed of “F”, “E”, and a fuel supply mark, and a bar graph indicating a predetermined fixed display portion 41a where the length changes in conjunction with the change in fuel in the tank. And a variable display portion 41b.

  In addition, polarizing plates 43 and 44 are attached to the liquid crystal cell 4 on the front surface and the back surface, respectively, so that polarized light necessary for display by the display unit 41 and the background unit 42 is formed.

  As shown in FIGS. 1 and 2, the transmissive reflective plate 5 is disposed between the liquid crystal cell 4 (polarizing plate 44) and the light source 3, and includes a substrate 51, a transflective layer 52, and a first coloring. A layer 53 and a second colored layer 54 are included.

  The substrate 51 is made of a colorless and transparent plate material made of, for example, a translucent synthetic resin, and has a size corresponding to the size of the liquid crystal cell 4.

  The transflective layer 52 is formed of, for example, a printing layer mixed with a pearl pigment, and is formed on the back surface of the substrate 51. The transflective layer 52 transmits light from the light source 3 to the liquid crystal cell 4 (front) side and the liquid crystal cell 4 (front) side. The optical characteristics of reflecting light incident on the liquid crystal cell 4 (front) side. Note that the color of the transflective layer 52 itself is, for example, milky white.

  In addition, the transflective plate 52 has a predetermined interval from the first colored layer 53 including the dot coloring portion 531 formed by dots that are transparent and that gradually changes the background portion of the display portion 41. And the 2nd coloring part 54 with the pattern arranged continuously is laminated | stacked. As shown in FIGS. 5 to 8, the second colored portion 54 in which the lattice shape, the shape in which the elliptical shape is cut out, and the like are evenly arranged is laminated so as to cover the dot colored portion 531, or the dots The color plate 531 may be printed in the same plate.

  The first colored layer 53 is composed of, for example, an aggregate of dots printed and formed at a predetermined density using light-transmitting ink, and appropriately colors the background portion 42 of the display portion 41 with the color shown in FIG. As shown in FIG. 5, the background portion 42 is divided into a plurality of areas in units of a tachometer TA, a speedometer SP, and a fuel meter FU, and each area is set to a different color.

 In addition, the second colored portion 54 has an opening ratio of 60% or more and 40% or less at a portion in contact with the tone jump Q. This is because the aperture ratio at which the tone jump occurs is about 50%, and in order to hide the tone jump, the aperture ratio needs to be smaller or larger than 50%.

In the present embodiment, the first colored layer 53 is formed on the substrate 51, but a substrate different from the substrate 51 is prepared, formed on the front surface or the back surface, and overlapped on the front surface side of the transflective plate 5. You may arrange.

  In the display device configured as described above, when the light source 3 is turned off, light such as natural light incident from the front side of the liquid crystal cell 4 illuminates the first and second colored layers 53 and 54 and transmits through the substrate 51. A part of the light is reflected by the semi-transmissive reflective layer 52 of the transmissive reflective plate 5 and passes through the substrate 51 and the first and second colored layers 53 and 54, thereby brightening the background portion 42. The display unit 41 that is in a non-transparent state due to voltage application is visually recognized dark by blocking light. Moreover, it has the non-contact area | region N to which an adjacent dot does not contact, and the contact area C to which an adjacent dot contacts, and the brightness changes rapidly in the boundary of the non-contact area N and the contact area C. Even if a tone jump Q that looks like this occurs, the boundary can be made inconspicuous by covering with the second coloring portion 54.

  Here, since the first colored layer 53 has a dot shape, light enters the semi-transmissive reflective layer 52 (the transmissive reflective plate 5) through the gap S of the dot colored portion 531 and is reflected as shown in FIG. Since the light exits through the gap S, the shortage of external light incident on the semi-transmissive reflective layer 52 (the transmissive reflective plate 5) is alleviated, thereby coloring the background portion 42 and the display portion 41 and the background portion. The contrast with 42 can be kept good.

  On the other hand, when the light source 3 is turned on, the light from the light source 3 passes through the transflective layer 53 and the substrate 52 and illuminates the colored layer. As a result, the display unit 41 and the background unit 42 are visually recognized with a predetermined contrast even when the light source 3 is turned on.

As described above, in the present embodiment, the liquid crystal cell 4 having the display unit 41 in which the transmission state and the non-transmission state are switched by selective voltage application between the pair of transparent electrodes, and the liquid crystal cell 4 are illuminated. The light source 3 is disposed between the light source 3 and the liquid crystal cell 4, and the incident light transmitted through the liquid crystal cell 4 and incident from the front side is reflected to the liquid crystal cell 4 side, and the backlight from the light source 3 is transmitted to the liquid crystal cell. In a display device including a transmissive reflection plate 5 that is transmissive to the four sides,
The transmissive reflective plate 52 includes a light-transmitting first coloring portion 53 that colors the background portion of the display portion 41, and second coloring portions 54 that are continuously arranged with a predetermined interval. ,
The first coloring portion 53 is composed of a dot coloring portion 531 in which the dot size gradually changes,
By covering the dot coloring portion 531, the second coloring portion 54 can make it difficult to visually recognize the boundary even if a tone jump phenomenon occurs.

  Moreover, in this embodiment, since the 2nd coloring part 54 is provided on the same surface as the dot coloring part 531, since the dot coloring part 531 can be printed by one printing, cost can be held down.

  Further, in the present embodiment, the second coloring unit 54 covers the tone jump Q generated by the dot coloring unit 531 so that it is difficult to visually recognize the boundary even if the tone jump phenomenon occurs.

DESCRIPTION OF SYMBOLS 1 Circuit board 2 Cell case 3 Light source 4 Liquid crystal cell 5 Transmission-type reflector 41 Display part 42 Background part 41a Fixed display part 41b Variable display part 43,44 Polarizing plate 51 Substrate 52 Semi-transmissive reflection layer 53 1st coloring part 54 1st 2 colored part 531 Dot colored part SP Speedometer TA Tachometer FU Fuel meter Q Tone jump S Gap

Claims (2)

A liquid crystal cell having a display portion that is switched between a transmissive state and a non-transmissive state by selectively applying a voltage between a pair of transparent electrodes, a light source that illuminates the liquid crystal cell, and between the light source and the liquid crystal cell A display device comprising: a transmissive reflector that is disposed and reflects incident light that is transmitted through the liquid crystal cell and is incident from the front side toward the liquid crystal cell side, and transmits backlight from the light source toward the liquid crystal cell side In
The transmissive reflector has a translucent first colored portion that colors a background portion of the display portion, and second colored portions that are continuously arranged with a predetermined interval,
The first colored portion is composed of a dot colored portion in which the dot size gradually changes,
The display device characterized in that the second coloring portion covers the dot coloring portion. The display device according to claim 1, wherein the second coloring portion covers a tone jump generated by the dot coloring portion.