JPH058502U - Infrared transparent filter - Google Patents

Abstract

(57) [Abstract] [Purpose] In an infrared transmission filter provided in front of a light receiving sensor for remote control using infrared rays, the appearance color of the infrared transmission filter without lowering the sensitivity of the light receiving sensor. It is to provide a means for coloring the above with a color other than black. [Structure] In the infrared transmission filter, a mixed material containing a strip of a transparent plastic substrate, a dye, and a pigment is stirred and dissolved, and this material is molded so that at least a part thereof forms a convex lens. It is a thing.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an infrared transmission filter provided in front of a light receiving sensor for remote control using infrared rays.

[0002]

[Prior Art]

 Remote control using infrared rays (hereinafter referred to as infrared remote control) is a technology that is often used in television receivers and the like. For example, as shown in FIG. 2, an adjusting unit 13 is provided below a television receiver (hereinafter referred to as a television) 10, and the adjusting unit 13 is provided with a light receiving sensor 12 for infrared remote control. An infrared transmission filter (hereinafter referred to as a filter) 11 is provided on the front surface of the sensor 12, and a control signal by infrared light emitted from a light emitting diode or the like on the front surface of the television 10 is received by the light receiving sensor 12. That is, the television 10 is controlled.

A conventional technique of the infrared transmission filter provided on the front surface of the light receiving sensor for the infrared remote controller will be described below with reference to FIGS. 2 to 4. Conventionally, the filter used for the light receiving part of the infrared remote controller is made by using several kinds of dyes in addition to a transparent base material (plastic material such as acrylic or polycarbonate), and is emitted from the remote control device of the equipment. The infrared light thus received can substantially pass through the filter, but the light in the visible light region is almost absorbed by the infrared light transmitting filter, and the visible light does not pass through this filter.

The spectral transmittance of the infrared transmission filter as described above is generally as shown in FIG. In the figure, the horizontal axis represents the wavelength of light in nm, the vertical axis represents the transmittance, and the wavelength of visible light is 400 to 750 nm. In other words, with this filter, only the red rays are transmitted, although they are slightly attenuated, but visible light is hardly transmitted. Moreover, reflection of light hardly occurs due to the characteristics of the dye used for coloring.

Therefore, the appearance color of the filter seen from the incident side of infrared rays is black because visible light is absorbed by the filter and there is no reflected light. As an infrared transmission filter, as shown in FIG. 4, there is a method in which a dye is printed on the back surface of the transparent base material 15 provided in the adjustment section 13 of the television. Appearance is limited to black or purple. The light receiving sensor 12 has a characteristic of being most sensitive to infrared rays having a wavelength of 950 nm to 1000 nm, for example.

As described above, the appearance color of the filter is almost black, which is a constraint on the appearance design of equipment such as a television. For example, if you want to unify the appearance of the television with a grayish color and not see anything other than the cathode ray tube and the panel, only the filter part is inevitably black. As a result, it reduces the chances. Therefore, even if an attempt is made to color the filter with a color other than black, coloring with a dye, for example, has almost no effect on the transmission of infrared rays, but it absorbs almost no visible light and does not reflect it. It will be black. In addition, when a pigment having a light reflection is added to the filter material for coloring, it reflects not only visible light but also infrared rays, which causes a decrease in infrared transmittance of the filter. There was a point.

[0007]

[Problems to be solved by the device]

 The present invention has been devised in view of the above problems, and it is an object of the present invention to provide a means for coloring the appearance color of an infrared transmission filter with a color other than black without lowering the luminous flux density in the light receiving sensor.

[0008]

[Means for Solving the Problems]

 SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides an infrared transmission filter arranged in front of a light receiving sensor for remote control using infrared rays, in which a strip of a transparent plastic substrate, a dye and a pigment are used. Is molded so that at least a part thereof forms a convex lens.

[0009]

[Action]

 Since the infrared transmissive filter contains a pigment in addition to the usual dye for infrared transmissive filters, a part of the visible light incident on the filter is reflected. Therefore, the appearance of the filter is colored in a color other than black. The infrared rays incident on the filter are partly absorbed by the pigment or the plastic substrate, but are condensed by the convex lens formed by the filter, and substantially the luminous flux in the light receiving sensor. The density does not decrease.

[0010]

【Example】

 Hereinafter, the infrared transmission filter of the present invention will be described with reference to FIGS. 1 to 3. FIG. 1 is a view showing an embodiment of the infrared transmission filter of the present invention. In FIG. 1, reference numeral 1 is an infrared ray transmission filter formed by a material made of a transparent plastic base strip, a dye, a pigment and the like, and a convex lens is formed on one side. is there. Further, the light receiving sensor 12 is arranged at a distance L from the surface of the convex lens on the central axis AA line passing through the substantially central portion of the filter 1. C is the focal point of the convex lens, and the distance from the surface of the convex lens is F.

In FIG. 1, a filter 1 is made by mixing a transparent plastic material strip, a dye for forming an infrared transmitting filter, a pigment for coloring, and the like with stirring, and putting them in a hopper of a molding machine. It is melted by heating and molded. When the proportion of the pigment to be mixed and stirred is small, the reflected light and coloring by the filter 1 are small, and the attenuation amount of infrared rays is small. On the other hand, when the proportion of the pigment mixed and stirred is large, the amount of reflected light and coloring by the filter 1 is large, but the amount of attenuation of infrared rays is also large. In any case, by mixing the pigments as described above, the appearance color of the filter 1 is colored in a color other than black.

In FIG. 1, for example, control light for an infrared remote controller emitted by a light emitting diode or the like enters the filter 1 from the left side of FIG. When the pigment mixed in the filter 1 is, for example, a white pigment, the incident light on the filter 1 reflects a part of visible light and infrared light, and the appearance color of the filter 1 becomes gray. .. Further, infrared rays are absorbed by the pigment mixed in the filter 1 and the plastic base material, and light is transmitted to the right of the filter 1 with some attenuation. However, visible light is absorbed by the filter 1 and hardly penetrates to the right of the filter 1.

A convex lens is formed on the right side surface of the filter 1, and the light incident from the left side of the filter 1 and transmitted to the right side is condensed. This has the effect of preventing the transmittance of infrared rays from decreasing due to the influence of the pigment mixed in the filter 1 and the decrease in the light flux density in the light receiving sensor 12 and the decrease in light receiving sensitivity as described above. I have it.

In FIG. 1, assuming that the density of the incident infrared ray is R1 and the infrared transmittance of the filter 1 is K, the infrared ray density R2 in the light receiving sensor 12 is R2 = K × It can be expressed as R1 {F / (FL)} 2. As is clear from the above equation, it is possible to give the light receiving sensor 12 an infrared ray having the same density as the infrared ray density of the incident light on the filter 1 depending on the setting of F and L in the above equation. That is, by forming a convex lens on the filter 1, it is possible to equivalently compensate for the decrease in the infrared transmittance due to the filter 1, and to carry out coloring to some extent by the pigment.

According to an experiment for changing the appearance color of the filter 1 to gray, when the pigment used is white, the K is 0.66, and the F is 30 mm and the L is 5.6 mm. , R1 and R2 in the above equation could be made substantially equal. As described above, in order to increase the degree of freedom in design, in order to color the appearance color of the infrared transmission filter to a color other than black, an appropriate amount of pigment is mixed in the infrared transmission filter, and the infrared transmission is It is possible to form a convex lens with the above-mentioned filter in order to compensate for the decrease in the refractive index so that the luminous flux density in the light receiving sensor does not substantially decrease.

[0016]

[Effect of the device]

 According to the infrared transmission filter of the present invention, the external color of the filter can be colored other than black without deteriorating the light receiving sensitivity of the infrared remote control, and the flexibility of the external design of the device using the infrared remote control is increased. Was able to be greatly improved.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a filter of the present invention.

FIG. 2 is a diagram illustrating an example of a television receiver.

FIG. 3 is a diagram showing a spectral transmittance of an infrared transmission filter.

FIG. 4 is a diagram showing an adjustment unit of a television receiver and a filter according to a dye printing method.

[Explanation of symbols]

 1 Filter of the present invention 10 Television receiver 11 Filter 12 Light receiving sensor 13 Adjustment unit of television receiver 15 Filter by dye printing

Claims (1)

[Claims for utility model registration] [Claim 1] In an infrared transmission filter disposed in front of a light receiving sensor for remote control using infrared rays, a strip of a transparent plastic substrate, a dye and a pigment are used. An infrared transmitting filter, characterized in that it is molded so as to form a convex lens at least in part by the mixed material containing.