JP3049119B2 - Light source temperature controller for image reading device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source temperature control device for an image reading apparatus using a fluorescent lamp as a light source for illuminating a document.

[0002]

2. Description of the Related Art Since the amount of light from a fluorescent lamp greatly changes depending on the temperature of the fluorescent lamp, it greatly affects the accuracy of image reading. For this reason, as described in, for example, Japanese Utility Model Laid-Open No. 2-119243, the temperature of the fluorescent lamp is detected, and when the detected temperature is equal to or lower than a certain value, the fluorescent lamp is heated by the heater.

[0003]

Conventionally, the temperature of the fluorescent lamp is raised only by the heater at the time of warm-up, and the temperature of the fluorescent lamp is adjusted only by the heater after the reading operation. For this reason, the time required to raise the temperature of the fluorescent lamp to a certain value becomes longer.

[0004]

According to a first aspect of the present invention, there is provided a transparent document table on which a document is placed, a fluorescent lamp held relatively reciprocally along a lower surface of the document table, An optical element for receiving the reflected light from the document, a detector for detecting the temperature of the fluorescent lamp, a heating element close to the back of the fluorescent lamp on the side opposite to the platen, and a power supply At the time of introduction
Turn on the fluorescent lamp until the detector detects a certain temperature.
Temperature control means for lighting, and the detection
When the temperature detected by the heater is below a certain value, the heating element is driven.
Temperature control means .

According to a second aspect of the present invention, there is provided a transparent apparatus on which an original is placed.
Reciprocating along the original platen and the underside of the platen
Receives reflected light from the original and a fluorescent lamp held freely.
An optical system element that emits light and a detection device that detects the temperature of the fluorescent lamp
Along the back of the fluorescent lamp opposite to the platen.
The heater and the detector are constant when the power is turned on.
The fluorescent lamp and the heating element are driven until the temperature of the fluorescent lamp is detected.
Temperature control means for causing the detector
The heating element is driven when the detected temperature is below a certain value.
It was constituted by temperature control means.

[0006]

[0007]

[0008]

According to the first aspect of the present invention, fluorescent light is used during warm-up.
The fluorescent lamp can be heated to a certain temperature by the heat generated by the lamp itself.
After the reading operation, the heater can be used to turn on the fluorescent lamp.
Since the temperature can be adjusted,
In some cases, the fluorescent lamp can be turned on only for reading operation.
And thus extend the life of the fluorescent lamp.
Wear.

According to the second aspect of the present invention, at the time of warm-up,
A certain amount of fluorescent light is generated by the heat of the fluorescent light itself and the heat of the heater.
Temperature can be increased and therefore warm up
The time can be shortened, and after the read operation shifts,
The heater can adjust the temperature of the fluorescent lamp.
After the reading operation is started, the fluorescent lamp is used for the reading operation.
Can only be lit, and therefore the fluorescent lamp life
You can extend your life.

[0010]

[0011]

[0012]

1 to 3 show an embodiment of the present invention.
It will be described based on. As shown in FIG. 2, a movable body 3 is provided along a lower surface of a transparent document table 2 on which a document 1 is placed so as to be reciprocally movable in the sub-scanning direction. The movable body 3 has a straight tube-type fluorescent lamp 4 whose axis is arranged along the width direction (main scanning) of the original 1, a refractive index distribution type lens 5 and a CCD image sensor 6 which are optical systems, respectively. And are attached. In addition, a heater 7 is disposed close to the rear surface of the fluorescent lamp 4 opposite to the document table 2, and a thermistor 8, which is a detector for detecting the temperature of the fluorescent lamp 4, is disposed close to the heater 7 as shown in FIG. Are located.

The temperature control operation for heating the fluorescent lamp 4 in such a configuration will be described with reference to the flowchart shown in FIG. First, the main switch is turned on.
Here, the temperature of the fluorescent lamp 4 is detected by the thermistor 8, and when the detected temperature of the thermistor 8 is lower than the optimal temperature stored in advance, the fluorescent lamp 4 is driven by the temperature control means. This temperature control means is constituted by a CPU (not shown) which operates based on program data. When the fluorescent lamp 4 is turned on, it is heated by its own heat, and when the temperature detected by the thermistor 8 reaches or exceeds the optimum temperature, the fluorescent lamp 4 is turned on.
Is maintained in the light-off state by the temperature control means. This process is a warm-up, and is then maintained in a standby state.

After the reading operation, if the detected temperature of the thermistor 8 is lower than the optimum temperature, the fluorescent lamp 4 is heated because the heater 7 is driven by the temperature control means.
When the temperature detected by the thermistor 5 reaches or exceeds the optimum temperature, the power supply to the heater 7 is cut off by the temperature control means. At the time of reading, the original 1 is illuminated by the fluorescent lamp 4,
The image of the original 1 is formed on the CCD image sensor 6 through the gradient index lens 5.

As described above, the reading operation is performed in a state where the temperature of the fluorescent lamp 4 reaches the optimum temperature, so that the original 1 can be irradiated with the reference light amount and the image of the original 1 can be faithfully read. Further, based on the temperature detected by the thermistor 8, the fluorescent lamp 4 is turned on to generate heat from the fluorescent lamp 4 itself and the heater 7.
, The temperature of the fluorescent lamp 4 can be quickly increased to a constant temperature.

[0016] Incidentally, a plurality of thermistors 8 for detecting the temperature of the fluorescent lamp 4 (detector) along the longitudinal direction of the fluorescent lamp 4 disposed, all of the thermistor 8 when power is turned on to detect a certain temperature The fluorescent lamp 4 or the heater 7 may be driven until the operation is completed. Thereby, the temperature change of each part of the fluorescent lamp 4 is detected by the individual thermistor 8, and the fluorescent lamp 4 is heated based on the detection result, thereby heating all parts of the fluorescent lamp 4 to a certain temperature or more. Can be.

A plurality of fluorescent lamps 4 illuminating the original 1
Is provided with a heater 7 and one or more thermistors 8 for each fluorescent lamp 4, and the temperature is detected by the thermistor 8 for each fluorescent lamp 4. If the detected temperature is lower than the optimum temperature, the fluorescent lamp 4 May be turned on to raise the temperature of the fluorescent lamp 4 by its own heat, or the temperature of the fluorescent lamp 4 may be raised by the heater 7. Thereby, even if the temperature changes of the fluorescent lamps 4 and the heaters 7 vary, the temperature can be accurately set for each fluorescent lamp 4.

[0018] Next, FIG. 4 an embodiment of the invention of claim 2
It will be described based on. Since the structure in FIGS. 2 and 3 is also applied to the present embodiment, only the heating operation of the fluorescent lamp 4 will be described with reference to the flowchart shown in FIG. First, the main switch is turned on. Thermistor 8
If the detected temperature is below the optimal temperature stored in advance,
The fluorescent lamp 4 and the heater 7 are driven by the temperature control means. This temperature control means is also constituted by a CPU (not shown) which operates based on the program data. The fluorescent lamp 4 is heated by its own heat generated by lighting and the heat of the heater 7, and when the temperature detected by the thermistor 8 reaches or exceeds the optimum temperature, the fluorescent lamp 4 and the heater 7 are kept in a non-driving state by the temperature control means. You. This process is warm-up,
After that, it is maintained in a standby state.

After the reading operation, if the temperature detected by the thermistor 8 is lower than the optimum temperature, the fluorescent lamp 4 is heated because the heater 7 is driven by the temperature control means.
When the temperature detected by the thermistor 8 reaches or exceeds the optimum temperature, the power supply to the heater 7 is cut off by the temperature control means. The reading operation is performed in this state.

As described above, at the time of warm-up, the heat generated by the fluorescent lamp 4 itself and the heat of the heater 7 can raise the temperature of the fluorescent lamp 4 to a constant temperature, so that the warm-up time can be shortened. After the transition to the reading operation, the temperature of the fluorescent lamp 4 can be adjusted by the heater 7, so that after the transition to the reading operation, the fluorescent lamp 4 can be turned on only for the reading operation. Can be extended.

[0021]

According to the first aspect of the present invention , a detector is provided when power is turned on.
Temperature control that turns on the fluorescent lamp until the device detects a certain temperature
Control means and the detection temperature of the detector
Temperature control means for driving the heating element when the temperature is below a certain value.
Because it is provided, the fluorescent lamp itself generates heat during warm-up
The fluorescent lamp can be raised to a certain temperature, and the reading
Adjust the temperature of fluorescent lamp by heater after shifting operation
After switching to the reading operation, turn on the fluorescent light.
It can be turned on only for the reading operation,
This has the effect of extending the life of the fluorescent lamp .

According to a second aspect of the present invention, when the power is turned on, the detector
Drive the fluorescent lamp and heating element until a certain temperature is detected.
Temperature control means, and after the read operation shifts, the detector is detected.
Temperature at which the heating element is driven when the output temperature is below a certain value
Control means are provided so that fluorescent lamps can be used during warm-up.
Keeps the fluorescent lamp at a certain temperature by its own heat and the heat of the heater
Can be increased and therefore warm-up time
Can be shortened, and the heater
The temperature of the fluorescent lamp can be adjusted by
After the operation transition, turn on the fluorescent lamp only for reading operation.
Lamps, thus extending the life of fluorescent lamps
It has the effect that it can be performed .

[0023]

[0024]

[Brief description of the drawings]

[1] relates to an embodiment of the invention of claim 1 is a flow chart showing the operation of heating the fluorescent lamp.

FIG. 2 is a front view thereof.

FIG. 3 is a rear view of the fluorescent lamp.

[4] relates to an embodiment of the invention of claim 2 is a flowchart showing the operation of heating the fluorescent lamp.

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G03B 27/72 G03B 27/54 H04N 1/04

Claims (2)

(57) [Claims] 1. A transparent document table on which a document is placed, a fluorescent lamp held relatively reciprocally along a lower surface of the document table, and an optical system for receiving light reflected from the document. An element, a detector for detecting the temperature of the fluorescent lamp, a heating element close to the back of the fluorescent lamp on the side opposite to the document table, and the detector detects a constant temperature when power is turned on. Until
Temperature control means for turning on the fluorescent lamp, and after shifting to the reading operation
Drives the heating element when the temperature detected by the detector is below a certain value.
A light source temperature control device for an image reading apparatus, comprising: a temperature control means for moving the light source. A transparent platen on which the document is placed;
Relatively movable back and forth along the underside of the platen
Fluorescent lamp and optical element for receiving light reflected from the document
A detector for detecting the temperature of the fluorescent lamp, and the fluorescent lamp
Fever close to the back of the platen
Body and the detector detects constant temperature at power on
Temperature control means for driving the fluorescent lamp and the heating element up to
And the detection temperature of the detector is constant after the reading operation is shifted.
A light source temperature control device for an image reading apparatus , comprising: a temperature control means for driving the heating element when the value is equal to or less than a value .