JPS631335Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to devices that perform various displays using liquid crystals, and in particular, in a transmission type liquid crystal display device that receives illumination light from behind, the front polarizing plate has a portion that corresponds to the electrode of the liquid crystal cell. In addition to forming a light-shielding colored part excluding parts such as letters and symbols,
A translucent colored part is formed in areas such as letters and symbols, and a rear polarizing plate is formed only in the part corresponding to the electrodes of the liquid crystal cell, and a translucent colored part is formed on the back of this rear polarizing plate. This structure allows for color display.

Embodiments of this invention will be described below with reference to the accompanying drawings.

The liquid crystal cell 1 consists of two transparent electrode plates 2 and 3 in which rectangular electrodes are formed horizontally in a line. A voltage difference is created between the electrodes. Both electrode plates 2 and 3 face each other with a small space interposed therebetween, and a TN liquid crystal 5 is sealed in this space.

Front and rear polarizing plates 6 and 7 are located on both sides of the liquid crystal cell 1 with their polarization axes parallel to each other, and behind the rear polarizing plate 7, an illumination light source 8 is arranged.

An explanation will be added regarding both the polarizing plates 6 and 7. The front polarizing plate 6 has a light-shielding black printed layer 9 formed on the parts corresponding to the electrodes of the liquid crystal cell 1 and parts such as characters and symbols, and has a transparent border color on the parts such as characters and symbols. A printed layer 10 is formed. Note that the light-shielding and light-transmitting printed layers 9 and 10 may be formed on either side of the front polarizing plate 6.

Further, the rear polarizing plate 7 is located only in the portion corresponding to the electrode of the liquid crystal cell 1, and is not provided in other portions.
A translucent red printed layer 11 is formed on the back surface of this polarizing plate 7, but this printed layer 11 is
If it is formed on the surface of the rear polarizing plate 7 that is in contact with the liquid crystal cell 1, the function of the rear polarizing plate 7 may be hindered, so it is desirable to form it on the back surface of the rear polarizing plate 7.

According to the liquid crystal display device having such a structure, when normal display is not performed, there is no potential difference between all the electrodes of both electrode plates 2 and 3, and the polarization axes of both polarizing plates 6 and 7 are parallel. Therefore, the portions corresponding to the electrodes that display measured values do not pass the light rays from the light source 8, and are displayed in a dark color, while only portions such as letters and symbols shine in a border color.

Next, the measured value of the detection unit increases, and both electrode plates 2,
When a potential difference occurs sequentially between the electrodes on the lower side of 3,
The light beam from the illumination light source 8 passes through only the portion corresponding to this electrode, so it shines in red, and the portions such as letters and symbols also shine in a border color as described above. For this reason, the potential between the electrodes of both electrode plates 2 and 3 changes in response to changes in the measured value of the detection unit, and the polarizing plate 7 provided on the back side of the rear polarizing plate 7 placed behind the liquid crystal cell 1 sequentially starts from the lower side. The color of the red printing layer 11 shines, and the parts such as letters and symbols always shine with the color of the edge color printing layer 10 provided on the front polarizing plate 6, making it extremely impressive in contrast to the dark color of other parts. Because it is displayed, the device is really easy to see for users who want to visually check it.

Note that this invention is not limited to the above example; for example, the liquid crystal cell 1 is placed behind the rear polarizing plate 7 described above.
A reflector may be provided to cover the entire rear surface, and in this case, the illumination light source 8 is placed in front of the front polarizing plate 6. Further, the light-shielding and light-transmitting portions 9, 10, and 11 are not limited to those formed by printing, and appropriate ones such as colored filters may be selectively used.

As explained above, according to this invention, parts such as letters and symbols always shine in the color of the translucent colored part formed on the front polarizing plate corresponding to the part,
Only the part of the liquid crystal cell that displays measured values, etc. that corresponds to the electrode part with a potential difference glows with the color of the translucent colored part provided on the back of the rear polarizing plate formed at the rear of the liquid crystal cell corresponding to the electrode part. Since the other portions are displayed in dark colors, there is no extra light beam that may confuse the visual recognition of the display, and a stable display operation can be obtained.

In addition, the rear polarizing plate only needs to be a portion corresponding to the electrodes of the liquid crystal cell, which requires less material than conventional ones, and can reduce costs.

Furthermore, by arbitrarily selecting the shape of the translucent colored parts of the dial, symbols, etc. provided on the front polarizing plate, a liquid crystal cell of the same shape can be used as a display device for different instruments, providing versatility. etc., it has a great deal of practical value.

[Brief explanation of drawings]

FIG. 1 is a structural diagram of an embodiment of this invention.
FIG. 2 is a front view of the same as above. 1... Liquid crystal cell, 2, 3... Electrode plate, 4... Spacer, 5... Liquid crystal, 6, 7... Polarizing plate.

Claims (1)

[Scope of utility model registration request] In devices that perform various displays using liquid crystals,
On the front polarizing plate, a light-shielding colored part is provided except for the part corresponding to the electrode part of the liquid crystal cell and the part for letters and symbols, and at the same time, a light-transmitting colored part is provided for the part for the letters and symbols, A liquid crystal display device characterized in that a rear polarizing plate is provided only in a portion corresponding to an electrode portion of a liquid crystal cell, and a translucent colored portion is provided on the back surface of the rear polarizing plate.