JP2004160731A - Image forming apparatus and temperature regulating method of quantity of light control board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus in which the effect of temperature characteristics of electronic components being used in a quantity of light control circuit can be reduced, and to provide a temperature regulating method of a quantity of light control board. <P>SOLUTION: The image forming apparatus comprises a light source temperature regulating section 1 for controlling the light source temperature, and a quantity of light control board 2 for controlling the quantity of light of the light source and has such a structure as a latent image is formed on a photosensitive body by scanning it with light from the light source, and when the light source temperature is higher than the environmental temperature around the light source, temperature of the quantity of light control board 2 is not monitored but satisfies a formula 1; (temperature of the control board)>(environmental temperature)+((light source temperature)-(environmental temperature))/2, within one hour after starting temperature regulation of the light source temperature. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus that forms a latent image on a photosensitive member by scanning light, and more particularly, to an APC that constantly monitors light quantity and performs feedback.
The present invention relates to an image forming apparatus that performs light amount control using (Automatic Power Control) and a method of controlling the temperature of a light amount control board.
[0002]
[Prior art]
Conventionally, the temperature of the light source has been controlled to stabilize the energy conversion efficiency and the emission wavelength of the light source. In particular, in the case of a silver salt film, as shown in FIG. 3, there is wavelength sensitivity dependency, and by controlling the temperature of the light source, the wavelength of the light source is stabilized, and the output image density is stabilized.
[0003]
For example, Japanese Patent Application Laid-Open No. H11-163873 discloses an accurate APC control by correcting a monitor current in accordance with a temperature in an image forming apparatus, in particular, a temperature of a PD (photodiode) for monitoring an LD light amount, and keeping the LD light amount constant. A technique for performing the above is disclosed.
[0004]
However, in the technique of Patent Literature 1, there is a problem in that the PD used for the light amount control has a temperature characteristic, and the light amount fluctuates due to the characteristic.
[0005]
Patent Literature 2 discloses a technique for controlling the temperature of a laser unit by providing high-precision temperature control means, and Patent Literature 3 discloses an exposure control device that corrects temperature characteristics of an LED light source. Patent Document 4 discloses a technique for controlling the temperature of circuit components.
[0006]
The technologies disclosed in Patent Documents 2, 3, and 4 use high-precision components or use a compensation circuit so that the temperature characteristics of a circuit system are electrically small. There is a problem that the amount of light fluctuates due to the influence of the temperature characteristics of the electronic components used in the circuit controlling the temperature.
[0007]
Further, in the conventional method, since the light amount control board is exposed to the environment, the influence of the environment cannot be sufficiently blocked. Further, when the light amount control board is exposed to the environment, there is a problem that a radio wave generated by the board is large. Further, in the technology described in the conventional patent document, the distance between the light source and the collimating lens is affected by the environmental temperature, and changes depending on the thermal expansion and the wavelength of the light source. As a result, there is a problem that optical characteristics such as a focus position fluctuate.
[0008]
[Patent Document 1] JP-A-2002-190641
[Patent Document 2] JP-A-2002-263848
[Patent Document 3] JP-A-9-101570
[Patent Document 4] Japanese Patent No. 2988767
[0009]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus and a temperature control method for a light quantity control board which can reduce the influence of the temperature characteristics of electronic components used in a circuit for controlling the light quantity.
[0010]
Another object of the present invention is to isolate a board for controlling the amount of light from the environment, thereby reducing the cost incurred for shielding radio waves generated by the board, and controlling convection to improve electronic components. It is an object of the present invention to provide an image forming apparatus and a method for controlling the temperature of a light amount control board, which improve the temperature stability of the image forming apparatus.
[0011]
Still another object of the present invention is to isolate the board for controlling the amount of light from the environment, thereby not only shielding the radio wave generated by the board, but also reduce the cost incurred for shielding and reduce convection. An object of the present invention is to provide an image forming apparatus and a method for controlling the temperature of a light quantity control board, which control the temperature stability of an electronic component more.
[0012]
Other objects of the present invention will become more apparent from the following description.
[0013]
[Means for Solving the Problems]
The above object is achieved by the following inventions.
[0014]
(Claim 1) An image forming apparatus comprising: a light source temperature control unit for controlling a light source temperature; and a light amount control board for controlling a light amount of the light source, and forming a latent image on a photosensitive member by scanning light from the light source. When the light source temperature is higher than the ambient temperature around the light source, the temperature of the light control board is monitored within one hour after the start of the temperature control of the light source without monitoring the temperature of the light control board. An image forming apparatus having a structure satisfying the following.
Equation 1
(Control board temperature)> (Ambient temperature) + ((Light source temperature) − (Ambient temperature)) / 2
[0015]
(2) An image forming apparatus comprising: a light source temperature controller for controlling a light source temperature; and a light amount control board for controlling a light amount of the light source, and forming a latent image on a photosensitive member by scanning light from the light source. When the light source temperature is lower than the ambient temperature around the light source, the temperature of the light control board is monitored within one hour after the start of the temperature control of the light source without monitoring the temperature of the light control board. An image forming apparatus having a structure satisfying the following.
Equation 2
(Temperature of control board) <(environmental temperature) + ((light source temperature)-(environmental temperature)) / 2
[0016]
(Claim 3) An image forming apparatus comprising: a light source temperature controller for controlling a light source temperature; and a light amount control board for controlling a light amount of the light source, wherein a latent image is formed on a photosensitive member by scanning light from the light source. When the light source temperature is higher than the ambient temperature around the light source, the temperature of the light control board is monitored within one hour after the start of the temperature control of the light source without monitoring the temperature of the light control board. And when the light source temperature is lower than the ambient temperature around the light source, the temperature of the light source control board becomes 1 after the start of the temperature control of the light source temperature without monitoring the temperature of the light source control board. An image forming apparatus having a structure that satisfies the following expression 2 within a time.
Equation 1
(Control board temperature)> (Ambient temperature) + ((Light source temperature) − (Ambient temperature)) / 2
Equation 2
(Temperature of control board) <(environmental temperature) + ((light source temperature)-(environmental temperature)) / 2
[0017]
(Claim 4) A light source temperature controller for controlling the light source temperature and a light amount control board for controlling the light amount of the light source are thermally connected by a substance having a thermal conductivity of 50 W / m · K or more. The image forming apparatus according to claim 1, 2 or 3, wherein
[0018]
(Claim 5) A light quantity control board is installed inside the light quantity control housing, and the light quantity control board is in direct or indirect contact with the light quantity control casing, and the light quantity control casing has a thermal conductivity of 50W. The image forming apparatus according to claim 1, wherein the image forming apparatus is formed of a material having a density of at least / m · K.
[0019]
(Claim 6) The image forming apparatus according to claim 5, wherein the light amount control housing is made of a metal having a thermal conductivity of 50 W / m · K or more.
[0020]
(7) The image forming apparatus according to any one of (1) to (6), wherein a light amount control PD is mounted on the light amount control board.
[0021]
(Claim 8) A light source temperature adjusting section for controlling a light source temperature includes a light source holding member for holding a light source, a heater and a temperature sensor provided in contact with the light source holding member, and the light source holding member is provided with a heat conducting member. The image forming apparatus according to claim 1, wherein the image forming apparatus is made of a substance having a rate of 50 W / m · K or more.
[0022]
(Claim 9) The image forming apparatus according to claim 8, wherein a planar heater is used as the heater.
[0023]
(Claim 10) A collimating lens is arranged on the optical axis of the light source, the collimating lens is held by a collimating lens holding member, and the collimating lens holding member is provided in contact with the light source holding member, and the collimating lens is The image forming apparatus according to claim 8, wherein the holding member is made of a substance having a thermal conductivity of 50 W / m · K or more.
[0024]
(11) The image forming apparatus according to any one of (1) to (10), wherein an LD is used as a light source.
[0025]
(Claim 12) The image forming apparatus according to any one of claims 1 to 11, wherein the photoconductor is a silver halide film.
[0026]
(13) An image forming apparatus comprising: a light source temperature control unit for controlling a light source temperature; and a light amount control board for controlling a light amount of the light source, and forming a latent image on a photosensitive member by scanning light from the light source. And controlling the temperature of the light amount control board so as to satisfy the following equation 1 within one hour after the start of the temperature control of the light source temperature when the light source temperature is higher than the ambient temperature around the light source. Control board temperature control method.
Equation 1
(Control board temperature)> (Ambient temperature) + ((Light source temperature) − (Ambient temperature)) / 2
[0027]
(14) An image forming apparatus comprising: a light source temperature control unit for controlling a light source temperature; and a light amount control board for controlling a light amount of the light source, and forming a latent image on a photosensitive member by scanning light of the light source. And controlling the temperature of the light amount control board so as to satisfy the following equation 2 within one hour after the start of the temperature control of the light source temperature when the light source temperature is lower than the ambient temperature around the light source. Control board temperature control method.
Equation 2
(Temperature of control board) <(environmental temperature) + ((light source temperature)-(environmental temperature)) / 2
[0028]
(15) An image forming apparatus comprising: a light source temperature control unit for controlling a light source temperature; and a light amount control board for controlling a light amount of the light source, and forming a latent image on a photosensitive member by scanning light from the light source. When the light source temperature is higher than the ambient temperature around the light source, the temperature of the light amount control board is controlled so as to satisfy the following equation 1 within one hour after the start of the temperature control of the light source temperature. Wherein the temperature of the light quantity control board is controlled so as to satisfy the following expression 1 within one hour after the start of temperature regulation of the light source temperature. Method.
Equation 1
(Control board temperature)> (Ambient temperature) + ((Light source temperature) − (Ambient temperature)) / 2
Equation 2
(Temperature of control board) <(environmental temperature) + ((light source temperature)-(environmental temperature)) / 2
[0029]
16. The light quantity control board according to claim 13, wherein when controlling the temperature of the light quantity control board, only the light source temperature is adjusted without monitoring the temperature of the light quantity control board. Temperature control method.
[0030]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail.
[0031]
A first feature of the image forming apparatus of the present invention is that when the light source temperature is T1, the environmental temperature T2, and the temperature T3 of the light amount control board, the light source temperature T1 is higher than the ambient temperature T2 around the light source, for example, When T1> T2, the temperature of the light quantity control board T3 satisfies the following equation 1 within one hour after the start of the temperature control of the light source temperature T1 without monitoring the temperature T3 of the light quantity control board. That is.
[0032]
Equation 1
T3> T2 + (T1-T2) / 2
[0033]
In the present invention, the light source temperature means a temperature measured by the temperature detecting sensor 103.
[0034]
The environmental temperature is an environmental temperature around the light source, and means a temperature outside the housing 200.
[0035]
The temperature of the light quantity control board is a temperature near the light quantity control board, but the temperature is not monitored. This is because not monitoring is a feature of the present invention.
[0036]
To explain with a specific example, when T1 is 38 ° C. and T2 is 15 ° C.,
T2 + (T1-T2) / 2 = 15 + (38-15) /2=26.5
[0037]
Therefore, since T1> T2, in this embodiment, the temperature of the light amount control board becomes T3> 26.5 ° C. within one hour after the start of temperature control.
[0038]
That is, in the present invention, the temperature of the light amount control board is a temperature closer to the light source temperature than the midpoint temperature between the ambient temperature of the light source and the light source temperature without any monitoring.
[0039]
Next, a second feature of the image forming apparatus of the present invention is that when the light source temperature T1 is lower than the ambient temperature T2 around the light source, that is, when T1 <T2, the temperature T3 of the light amount control board is monitored. In addition, the light amount control board has a structure in which the temperature T3 of the light amount control board satisfies the following expression 2 within one hour after the start of the temperature control of the light source temperature.
[0040]
Equation 2
T3 <T2 + (T1-T2) / 2
[0041]
To explain with a specific example, when T1 is 20 ° C. and T2 is 38 ° C.,
T2 + (T1−T2) / 2 = 38 + (20−38) / 2 = 29
[0042]
Therefore, since T1 <T2, in this embodiment, the temperature of the light amount control board becomes T3 <29 ° C. within one hour after the start of temperature control.
[0043]
That is, as in the first embodiment, the temperature of the light amount control board is closer to the light source temperature than the midpoint temperature between the ambient temperature of the light source and the light source temperature without any monitoring.
[0044]
Next, a third feature of the image forming apparatus of the present invention is that a more reliable temperature control can be realized in a mode in which the first mode and the second mode are combined.
[0045]
That is, the third feature is that when the light source temperature T1 is higher than the ambient temperature T2 around the light source, for example, when T1> T2, the light amount control board can be monitored without monitoring the temperature T3 of the light amount control board. When the temperature of T3 has a structure that satisfies Equation 1 within one hour after the start of the temperature control of the light source temperature T1, and the light source temperature T1 is lower than the ambient temperature T2 around the light source, that is, when T1 <T2 And a structure in which the temperature T3 of the light quantity control board satisfies the above expression 2 within one hour after the start of the temperature control of the light source temperature without monitoring the temperature T3 of the light quantity control board.
[0046]
Explaining in a specific example, when T1 is 38 ° C. and T2 is 15 ° C., T1> T2. Therefore, the temperature of the light amount control board becomes T3> 26.5 ° C. within one hour after the start of temperature control.
[0047]
When T1 is 20 ° C. and T2 is 38 ° C., T1 <T2, so that the temperature of the light amount control board becomes T3 <29 ° C. within one hour after the start of temperature control.
[0048]
That is, the temperature of the light amount control board is a temperature closer to the light source temperature than the midpoint temperature of the ambient temperature of the light source and the light source temperature without any monitoring.
[0049]
Next, a preferred embodiment of the present invention will be described.
[0050]
FIG. 1 is a schematic cross-sectional view illustrating an example of the image forming apparatus of the present invention. In FIG. 1, reference numeral 1 denotes a light source temperature adjustment unit that controls a light source temperature, and a light source holding member 101 that holds a light source 100; A heater 102 and a temperature sensor 103 provided in contact with the light source holding member 101 are provided.
[0051]
As the light source 100, for example, a semiconductor laser (laser diode; hereinafter, abbreviated as LD) is used, and the LD 1 emits a light beam having a predetermined narrow-band wavelength and optical output. Emit black colored light by light irradiation. Note that an LD that forms each of Y (yellow), M (magenta), and C (cyan) may be used.
[0052]
The light source holding member 101 is preferably a member capable of conducting heat, more preferably a substance (metal) having a heat conductivity of 50 W / m · K or more, and further preferably an Al (aluminum) metal (heat conductivity of 237 w / m · K). C).
[0053]
The heater 102 is configured to be able to supply heat energy from a heater electrode (not shown), and is held in contact with the light source holding member 101. To be provided in contact with the light source holding member 101 means that it is only necessary to be configured to be able to conduct heat, and it is not necessary to be provided directly.
[0054]
It is preferable to use a planar heater as the heater 102. Since the shape of the planar heater can be freely designed, the degree of freedom in heating is increased, and there is an effect that an optimum temperature distribution can be created.
[0055]
The temperature sensor 103 is preferably provided near the LD 100 for measuring the light source temperature. As the temperature sensor 103, for example, a thermistor can be used.
[0056]
Control of the light source temperature can be performed by controlling the amount of electric energy sent to the heater electrode.
[0057]
Reference numeral 104 denotes a superimposition board. The superimposition board 104 has a function of applying high frequency superimposition to the LD 100 at a predetermined frequency. For example, the superimposition board 104 turns off / on the LD drive current at 480 MHz. Reference numeral 105 denotes an electrode for supplying an LD drive current.
[0058]
Reference numeral 106 denotes a lid that covers the superposition board 104, and a space 107 is formed between the lid 106 and the superposition board 104.
[0059]
Reference numeral 108 denotes a collimating lens arranged on the optical axis X of the light source 100. The collimating lens 108 is held by a collimating lens holding member 109.
[0060]
The collimating lens holding member 109 is provided in contact with the light source holding member 101. Attached means that it is only necessary to be configured to be capable of conducting heat (to be thermally connected), and may be provided indirectly in contact with another metal therebetween. . Such thermal connection reduces the effects of thermal expansion and light source wavelength fluctuation, thereby improving the optical characteristics such as the focus position.
[0061]
In this embodiment, the collimating lens holding member 109 is preferably a member capable of conducting heat, more preferably a substance (metal) having a thermal conductivity of 50 W / m · K or more, and further preferably Al (aluminum) metal (thermal conductivity). 237 w / m · ° C.).
[0062]
Reference numeral 110 denotes a sampling lens that is disposed on the optical axis X of the light source 100 and that performs sampling for controlling the light amount of the LD with an LD light amount control board described later. The sampling lens 110 is held by a sampling holding member 111.
[0063]
In this embodiment, the sampling holding member 111 is held by a connecting member 112 that thermally connects the collimating lens holding member 109 and a light quantity control board (described later).
[0064]
The sampling holding member 111 and the connecting member 112 are preferably members capable of conducting heat, more preferably a substance (metal) having a thermal conductivity of 50 W / m · K or more, and further preferably Al (aluminum) metal (thermal conductivity). 237 w / m · ° C.).
[0065]
Reference numeral 2 denotes an LD light amount control board, and the LD light amount control board 2 is held inside an LD light amount control housing 200.
[0066]
The light amount control housing 200 includes a substrate 201 and a lid 202. A base plate 203 serving as a spacer is fixed on the substrate 201, and the LD light amount control board 2 is detachably fixed on the base plate 203.
[0067]
Photodiodes (PD) 204 are mounted and fixed on the upper and lower surfaces of the LD light quantity control board 2 in the drawing, and the PD 204 is mounted inside the light quantity control housing 200.
[0068]
Reference numerals 205 and 206 denote electronic components provided on the upper surface of the LD light quantity control board 2 in the drawing. The electronic components 205 and 206 are also mounted inside the light quantity control housing 200.
[0069]
It is preferable that the LD light quantity control board 2 is thermally isolated from an external environment by a light quantity control housing 200. Due to this thermal isolation, the influence of the temperature characteristics of the electronic components used in the circuit for controlling the light amount is reduced, so that the light amount is stabilized and stable image formation is possible. Further, since the influence of the temperature characteristics of the PD used for the light amount control is reduced, the light amount is stabilized, and stable image formation is possible.
[0070]
It is preferable that the light amount control housing 200 is made of metal. By using a metal case 200 surrounding the LD light quantity control board, the effect of shielding radio waves generated by the board can also be achieved.
[0071]
The substrate 201, the lid 202, the base plate 203, and the LD light amount control board 2 constituting the LD light amount control housing 200 may be members that can conduct heat, and preferably have a heat conductivity of 50 W / m · K or more. It is a substance (metal), more preferably Al (aluminum) metal (thermal conductivity: 237 w / m · ° C.).
[0072]
About 90% of the laser light from the LD 100 is transmitted, and the remaining about 10% is reflected by the sampling lens 110 and reaches the photodiode 204.
[0073]
The value of the light amount measured by the photodiode 204 is sent to the LD light amount control board 2, and the board 2 controls the drive current of the LD 100 so that the light amount of the LD 100 becomes a target value.
[0074]
As a result of the above-described configuration, the light source temperature control unit 1 and the LD light amount control board 2 are preferably in a state of being thermally connected by a substance having a thermal conductivity of 50 W / m · K or more.
[0075]
That is, the heat energy of the heater 102 can be transmitted to the LD light amount control board 2 via the light source holding member 101, the collimating lens holding member 109, and the connecting member 112.
[0076]
Therefore, the influence of the temperature characteristics of the electronic components 205 and 206 and the PD 204 used in the circuit for controlling the light amount is reduced, so that the light amount is stabilized and stable image formation is possible.
[0077]
Next, the operation of the image forming apparatus of the present invention will be described with reference to FIG.
[0078]
FIG. 2 is a schematic diagram showing an example of an electric circuit of the image forming apparatus of the present invention. As shown in FIG. 2, the LD 100, the temperature sensor 103, and the heater electrodes of the heater 102 (shown in FIG. ) Are electrically connected.
[0079]
The PD 204 is electrically connected to the LD light amount control board 2, a part of the light emission amount of the LD 100 is guided to the PD 204 by the sampling lens 110, and the drive current of the LD 100 is controlled so that the light amount becomes a target value. .
[0080]
The drive current control signal and the superimposition control signal are sent from the LD light amount control board 2 to the superposition board 104. In this control, the LD light amount control board 2 has acquired a signal indicating that the LD 100 is ON.
[0081]
The superimposition board 104 that has acquired such a signal applies an LD drive current to the LD 100 by turning it off / on at, for example, 480 MHz, and superimposes the high frequency on the LD 100 to control the light emission of the LD.
[0082]
Light emission power is supplied from the power supply board 207 to the superposition board 104 via the LD light amount control board 2. The power supply board 207 receives ± 12 V, generates ± 5 V, and supplies 5 V and 12 V to the superimposition board 104.
[0083]
It is preferable that the drive current and the light amount are monitored and displayed by a monitor display signal from the LD light amount control board 2.
[0084]
Reference numeral 208 denotes a D / A conversion board, which inputs a digital image signal transmitted from a main board (not shown) and converts it to analog 0-1V.
[0085]
Reference numeral 209 denotes a temperature control board, which inputs electric energy of +24 V, sends the electric energy to the heater 102, and secures heat energy of the heater 102.
[0086]
Reference numeral 113 denotes a polygon, which scans a photosensitive member (not shown) at a wide angle by a drive current from a polygon driver 114. A voltage of +24 V is supplied from the main substrate to the polygon driver 114, and an ON / OFF signal is also input to control the driving.
[0087]
In the present invention, the photoreceptor is preferably a silver salt film. The silver salt film has a wavelength sensitivity dependency, and by performing the temperature control of the present invention, the wavelength of the light source is stabilized, and the output image density is stabilized. The silver salt film is not particularly limited as long as it is a silver halide photographic light-sensitive material. For example, a heat-developable silver halide photographic light-sensitive material can be mentioned as a preferable example. This is because a heat-developable photosensitive material generally has a large wavelength sensitivity dependency, and the effect of the present invention becomes more remarkable.
[0088]
An H-SYNC sensor 115 detects whether or not an H-SYNC signal has been generated. The H-SYNC sensor is a sensor for generating a synchronization timing when writing an image.
[0089]
Next, the temperature adjustment of the LD light quantity control board 2 of the present invention will be described. The LD temperature T1 is detected by the temperature sensor 103. The environmental temperature T2 is a temperature outside the light quantity control board 2, and is detected by a normal temperature sensor. The temperature T3 of the light quantity control board is not monitored.
[0090]
The measured temperatures are supplied as digital data to a CPU (not shown),
T1> T2: Equation 1 T3> T2 + (T1−T2) / 2
T1 <T2: Equation 2 T3 <T2 + (T1−T2) / 2
[0091]
It is determined whether any of the above expressions 1 and 2 is satisfied. If the expression 1 is satisfied, the temperature T3 of the light amount control board is set to satisfy the expression 1 within one hour after the start of the temperature control of the light source temperature T1. Then, the temperature of T1 is adjusted.
[0092]
The temperature control signal of T1 is sent to the temperature control board 209. The control board 209 sends the sent control signal to the heater 102 on the superimposition board side to control the heater temperature.
[0093]
Similarly, when Expression 2 is satisfied, a control signal is sent to the temperature control board 209 to adjust the temperature so that the temperature T3 of the light amount control board satisfies Expression 2 within one hour after the start of temperature adjustment. The control board 209 sends the sent control signal to the heater 102 on the superimposition board side to control the heater temperature.
[0094]
Thus, when the heater temperature is adjusted, the temperature T3 of the light amount control board is adjusted without monitoring within one hour.
[0095]
One embodiment of the method for controlling the temperature of the light amount control board of the present invention has already been made clear by the above description. That is, in the above embodiment, the temperature on the LD light amount control board 2 side is adjusted by adjusting the light source side temperature without monitoring the LD light amount control board 2 side temperature. Although this embodiment is a preferred embodiment, the temperature control method for the light quantity control board of the present invention includes a mode of monitoring the temperature on the LD light quantity control board 2 side.
[0096]
【The invention's effect】
As described above, according to the first, second, and third aspects of the invention, the influence of the temperature characteristics of the electronic components used in the circuit that controls the light amount can be reduced.
[0097]
According to the fourth aspect of the present invention, the light source temperature control unit for controlling the light source temperature and the light amount control board for controlling the light amount of the light source are thermally connected by a substance having a thermal conductivity of 50 W / m · K or more. Accordingly, the influence of the temperature characteristics of the electronic components used in the circuit for controlling the light amount can be reduced.
[0098]
According to the invention described in claim 5, the light quantity control board is installed inside the light quantity control casing, and the light quantity control board is in direct or indirect contact with the light quantity control casing, Is made of a substance having a thermal conductivity of 50 W / m · K or more, the influence of the temperature characteristics of the electronic components used in the circuit for controlling the light intensity is reduced, so that the light intensity is stable and stable. Image formation becomes possible.
[0099]
According to the invention described in claim 6, the light amount control housing is made of a metal having a thermal conductivity of 50 W / m · K or more, so that the housing surrounding the LD light amount control board is made of metal. Also, the effect of shielding radio waves generated by the board can be achieved.
[0100]
According to the seventh aspect of the present invention, since the light quantity control board is mounted with the light quantity control PD, the influence of the temperature characteristic of the PD is reduced, so that the light quantity is stabilized and stable image formation is possible. It becomes.
[0101]
According to the invention described in claim 8, the light source temperature adjusting section for controlling the light source temperature includes the light source holding member for holding the light source, the heater and the temperature sensor provided in contact with the light source holding member, and the light source holding member. Since the member is made of a substance having a thermal conductivity of 50 W / m · K or more, the temperature can be monitored and adjusted in the light source temperature adjusting section, and a heat source can be supplied to the LD light quantity control board side. I do.
[0102]
According to the ninth aspect of the present invention, since the shape can be freely designed by using a planar heater as the heater, the degree of freedom in heating is increased, and there is an effect that an optimum temperature distribution can be created. The planar heater also has the effect of reducing heat radiation and reducing the capacity of the heater.
[0103]
According to the tenth aspect of the present invention, a collimating lens is disposed on the optical axis of the light source, the collimating lens is held by a collimating lens holding member, and the collimating lens holding member is provided in contact with the light source holding member. The collimating lens holding member is made of a material having a thermal conductivity of 50 W / m · K or more, so that the heat source on the light source temperature control unit side can be supplied to the LD light quantity control board side, and the thermal expansion and the light source wavelength By reducing the influence of the fluctuation, optical characteristics such as a focus position are improved.
[0104]
According to the eleventh aspect, when the LD is used as the light source, the temperature control effect of the present invention functions well.
[0105]
According to the twelfth aspect of the present invention, when the photosensitive member is a silver halide film having wavelength sensitivity dependency, the temperature of the light source is stabilized by performing the temperature control of the present invention, and the output image density is stabilized. effective.
[0106]
According to the inventions of claims 13, 14 and 15, since the temperature of the light quantity control board is controlled together with the light source temperature, the influence of the temperature characteristics of the electronic components used in the circuit controlling the light quantity can be reduced.
[0107]
According to the present invention, not only the effect of reducing the influence of the temperature characteristics of the electronic components used in the circuit for controlling the light amount can be exerted, but also the temperature of the LD light amount control board is not monitored. By adjusting the temperature on the light source side and by adjusting the temperature on the LD light amount control board side, it is easier to control the temperature than when monitoring the temperature of both the light source and the light amount control board. And less energy for temperature control.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view showing an example of an image forming apparatus of the present invention.
FIG. 2 is a schematic diagram showing an example of an electric circuit of the image forming apparatus of the present invention.
FIG. 3 is a graph showing the wavelength sensitivity dependence of a silver halide film.
[Explanation of symbols]
1: Light source temperature controller
100: Light source
101: Light source holding member
102: heater
103: Temperature sensor
104: Superposition board
105: electrode
106: Lid
107: Space
108: Collimating lens
109: Collimating lens holding member
110: Sampling lens
111: Sampling holding member
112: Connecting member
113: Polygon
114: Polygon driver
115: H-SYNC sensor
2: LD light quantity control board
200: LD light amount control housing
201: Substrate
202: Lid
203: Base plate
204: Photodiode (PD)
205, 206: electronic components
207: Power supply board
208: D / A conversion board
209: Temperature control board

Claims (16)

An image forming apparatus comprising: a light source temperature control unit for controlling a light source temperature; and a light amount control board for controlling a light amount of the light source, wherein the light source temperature is controlled by scanning the light of the light source to form a latent image on a photosensitive member. When the temperature of the light amount control board is higher than the ambient temperature of the light source without monitoring the temperature of the light amount control board, the temperature of the light amount control board satisfies the following equation 1 within one hour after the start of the temperature control of the light source temperature. An image forming apparatus comprising:
Equation 1
(Control board temperature)> (Ambient temperature) + ((Light source temperature) − (Ambient temperature)) / 2 An image forming apparatus comprising: a light source temperature control unit for controlling a light source temperature; and a light amount control board for controlling a light amount of the light source, wherein the light source temperature is controlled by scanning the light of the light source to form a latent image on a photosensitive member. When the temperature of the light amount control board is lower than the ambient temperature of the light source without monitoring the temperature of the light amount control board, the temperature of the light amount control board satisfies the following expression 2 within one hour after the start of temperature control of the light source temperature. An image forming apparatus comprising:
Equation 2
(Temperature of control board) <(environmental temperature) + ((light source temperature)-(environmental temperature)) / 2 An image forming apparatus comprising: a light source temperature control unit for controlling a light source temperature; and a light amount control board for controlling a light amount of the light source, wherein the light source temperature is controlled by scanning the light of the light source to form a latent image on a photosensitive member. When the temperature of the light quantity control board is higher than the ambient temperature of the light source, the temperature of the light quantity control board satisfies the following equation 1 within one hour after the start of the temperature control of the light source temperature without monitoring the temperature of the light quantity control board. And, when the light source temperature is lower than the ambient temperature around the light source, the temperature of the light control board is monitored within one hour after the start of the temperature control of the light source temperature without monitoring the temperature of the light control board. An image forming apparatus having a structure satisfying Expression 2.
Equation 1
(Control board temperature)> (Ambient temperature) + ((Light source temperature) − (Ambient temperature)) / 2
Equation 2
(Temperature of control board) <(environmental temperature) + ((light source temperature)-(environmental temperature)) / 2 2. The light source temperature controller for controlling the light source temperature and a light amount control board for controlling the light amount of the light source are thermally connected by a substance having a thermal conductivity of 50 W / m · K or more. 4. The image forming apparatus according to 2, 3 or 4. A light quantity control board is installed inside the light quantity control housing, and the light quantity control board is in direct or indirect contact with the light quantity control casing, and the light quantity control casing has a thermal conductivity of 50 W / m · K or more. The image forming apparatus according to any one of claims 1 to 4, wherein the image forming apparatus is made of the following material. The image forming apparatus according to claim 5, wherein the light amount control housing is made of a metal having a thermal conductivity of 50 W / mK or more. The image forming apparatus according to claim 1, wherein a light amount control PD is mounted on the light amount control board. A light source temperature control unit that controls a light source temperature includes a light source holding member that holds a light source, a heater and a temperature sensor provided in contact with the light source holding member, and the light source holding member has a thermal conductivity of 50 W / m · The image forming apparatus according to any one of claims 1 to 7, wherein the image forming apparatus is made of a substance of K or more. The image forming apparatus according to claim 8, wherein a planar heater is used as the heater. A collimating lens is arranged on the optical axis of the light source, the collimating lens is held by a collimating lens holding member, the collimating lens holding member is provided in contact with the light source holding member, and the collimating lens holding member is connected to a heat conducting member. The image forming apparatus according to claim 8, wherein the image forming apparatus is made of a substance having a rate of 50 W / m · K or more. The image forming apparatus according to claim 1, wherein an LD is used as a light source. The image forming apparatus according to claim 1, wherein the photoconductor is a silver halide film. An image forming apparatus comprising: a light source temperature control unit for controlling a light source temperature; and a light amount control board for controlling a light amount of the light source, wherein the light source temperature is controlled by scanning the light of the light source to form a latent image on a photosensitive member. Wherein the temperature of the light amount control board is controlled so as to satisfy the following equation 1 within one hour after the start of the temperature control of the light source temperature. Method.
Equation 1
(Control board temperature)> (Ambient temperature) + ((Light source temperature) − (Ambient temperature)) / 2 An image forming apparatus comprising: a light source temperature control unit for controlling a light source temperature; and a light amount control board for controlling a light amount of the light source, wherein the light source temperature is controlled by scanning the light of the light source to form a latent image on a photosensitive member. Wherein the temperature of the light amount control board is controlled so as to satisfy the following expression 2 within one hour after the start of the temperature control of the light source temperature. Method.
Equation 2
(Temperature of control board) <(environmental temperature) + ((light source temperature)-(environmental temperature)) / 2 An image forming apparatus comprising: a light source temperature control unit for controlling a light source temperature; and a light amount control board for controlling a light amount of the light source, wherein the light source temperature is controlled by scanning the light of the light source to form a latent image on a photosensitive member. If the ambient temperature is higher than the ambient temperature of the light source, the temperature of the light amount control board is controlled so as to satisfy the following equation 1 within one hour after the start of the temperature control of the light source temperature, and the light source temperature is the environmental temperature around the light source. A temperature control method for the light quantity control board, comprising: controlling the temperature of the light quantity control board so as to satisfy the following expression 1 within one hour after the start of temperature regulation of the light source temperature.
Equation 1
(Control board temperature)> (Ambient temperature) + ((Light source temperature) − (Ambient temperature)) / 2
Equation 2
(Temperature of control board) <(environmental temperature) + ((light source temperature)-(environmental temperature)) / 2 16. The method for controlling the temperature of a light quantity control board according to claim 13, wherein, when controlling the temperature of the light quantity control board, only the light source temperature is adjusted without monitoring the temperature of the light quantity control board.

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